Testout Labsim 1-3

Combination Ratchet/Screwdriver

A combination ratchet is a ratcheting handle with interchangeable bits that provides multiple features in a single tool. Bit ends can be replaced with Phillips and flat-head screwdrivers, hex sockets, and torx (star-shaped) bits. The ratcheting handle allows you to drive the screw without repositioning the driver. Most computer components use Phillips head screws.

Shell

A command line interface.

Operating system

A set of programs that acts as an interface between the applications that are running on a computer and the computer's hardware.

Cathode Ray Tube (CRT)

A vacuum tube used to display images that is commonly used in computer monitors.

Power supply tester

A special multimeter used to test output from a PC power supply.

Peripheral device

A device that connects to a computer, such as a monitor or printer.

Line conditioner

A device that modifies power signals to remove noise and create a smooth AC electrical signal.

Surge suppressor

A device that protects systems from damage from a power surge by suppressing the over-voltage.

Surge protector

A device that protects systems from over-voltages by switching the system off.

Uninterruptible power supply (UPS)

A device that provides battery power to a computer in case of an under-voltage or power failure.

Capacitor

A device that stores an electric charge.

DVI

A digital visual interface (DVI) port is used to connect display devices. DVI ports: Carry either an analog signal, a digital signal, or both. Support one of two cable and connector types, single link or dual link.

Material Safety Data Sheet (MSDS)

A document that contains safe handling and disposal processes for dangerous materials.

Firmware

A special type of software that is embedded in the read-only memory of a hardware component. A BIOS chip is an example of firmware.

Standby Power Supply (SPS)

A standby power supply is an offline device that switches over to provide power when an undervoltage occurs. If the switchover is not fast enough, the computer loses power.

Antistatic wrist strap

A strap that connects you to an antistatic pad to prevent static electricity from damaging computer components.

Application

A subclass computer program that is designed for end users.

Surge Protector

A surge protector protects against overvoltages by switching a device off before an overvoltage can damage it. A power strip provides multiple power outlets from a single plug-in, but is not necessarily a surge protector. Surge protectors can be destroyed by surges and lose their ability to protect. Consider using a surge protector with an indicator light to show whether it is working correctly.

Surge Suppressor

A surge suppressor conditions power so that overvoltages don't reach devices.

Driver (Windows)

A driver is a type of computer program that enables the operating system to interact with hardware devices.

Change order form

A form that must be completed and submitted to a change board to request permission to change a project's purpose, scope, schedule, budget, team, or other significant component.

Chipset

A group of chips that facilitates communication between the processor, memory, and peripheral devices.

Multimeter

A handheld device with a digital readout used to test electrical properties.

Three-Pronged Parts Retriever

A three-pronged parts retriever is used to grasp and retrieve small parts that have fallen into areas that are difficult to reach.

Cable tester

A tool that verifies that network signals can travel throughout a network.

Driver

A type of computer program that enables the operating system to interact with hardware devices.

Line Conditioner

A line conditioner modifies the power signal to remove noise and create a smooth alternating current (AC) signal.

Backout plan

A plan for returning affected systems and hardware to their original state if a new implementation fails.

IC insertion and extraction tool

A plastic and metal tool used to add and remove integrated circuit chips.

Power Supply Tester

A power supply tester is a custom multimeter used to test output from a PC power supply. The power supply tester has multiple connectors to test the output for each connector type.

Change board

A predetermined group of people that must approve proposed changes to a project that is underway.

Support manual

A motherboard's support manual is an excellent source of information. Support manuals contain technical specifications as well as diagrams that identify the motherboard's components. If you are missing a motherboard's support manual, check the manufacturer's website.

Combination ratchet/screwdriver

A multi-tool with interchangeable bits.

Multimeter

A multimeter is a device that tests various electrical properties. For example, most multimeters can measure: AC and DC voltage Current (amps) Resistance (ohms) Capacitance Frequency

Multi-Core

A multiple core processor has multiple processors within a single processor package. Dual-core, triple-core, and quad-core processors are typical in desktop systems. Multi-core systems enable the operating system to run multiple applications simultaneously. Without multiple processors, applications appear to run at the same time, but must wait their turn for processing time from the single processor. Some applications can be written to execute on multiple processors at the same time. Some motherboards use two (or more) processor sockets to provide a multiple processor solution. Multi-core processors use a single motherboard socket to support multiple processors.

Mac OS

A proprietary closed-source, operating system.

SODIMM

A SODIMM (small outline dual in-line memory module) is a smaller DIMM used in laptops. SODIMMs are much smaller than other memory, perfect for notebook computers. Notice the notch slightly off center in the 144-pin SODIMM. 144-pin SODIMMs are used by SDRAM, DDR, and DDR2 memory. On the 200-pin SODIMM, notice that the notch is farther off center than the 144-pin SODIMM. You might also be able to notice the higher pin density. 200-pin SODIMMs are used by DDR2 and DDR3 memory

POST Card

A POST card is an expansion board that you insert into an expansion slot. It is typically used to troubleshoot a computer system that doesn't start up correctly. The POST card displays output from the BIOS during the Power-On Self-Test (POST).

CPU Manufacturer

Intel and AMD are the two major producers of processors used in modern PCs. Both Intel and AMD processors work in PC systems and support Windows software. Intel has a larger market share, while AMD processors generally cost less. Processor performance and special features vary between models and manufacturers.

7. Ensure satisfaction

After the problem is fixed, ensure the customer's satisfaction and explain what you did to fix the problem. If possible, have the user perform the task to make sure that they understand and accept that the problem has been resolved.

Expansion slots

Allow you to expand the capabilities of your computer.

su

Allows you to switch user accounts. su - (su with a space and a hyphen) is used to switch to the root user with the home directory and environment variables assigned to the root user.

Antistatic pad

An insulated covering that prevents static electricity from moving between objects and damaging computer components.

IC Insertion and Extraction Tool

An IC insertion and extraction tool is used to add or remove integrated circuit chips that are used on motherboards and some computer components. For example, on some motherboards, you can use the IC insertion and extraction tool to change the BIOS chip.

2. Back up the system

Before making changes to the system, back up user and system data (or make sure a recent backup exists). While some changes can be made without affecting user data, you should back up data to protect against unintentional data loss caused by making changes.

Case fans

Case fans create a pressurized system that allows air to flow through the case in a specific way. Intake fans (at the front) pull air inside the case to cool components. Outtake fans (at the back and top) exhaust warm air from inside the case. Some cases have intake fans on the side case cover. Fan filters can be installed to keep dust and debris inside the case to a minimum.

RCA

An RCA connector on a sound card is used for coaxial digital I/O for S/PDIF audio. While RCA connectors can be used for analog audio, RCA connectors on a sound card are normally used for S/PDIF digital audio.

Antistatic Pad/Wrist Strap

An antistatic pad provides an insulated covering to prevent static electricity from moving between objects and damaging computer components. When working with computer components, use a wrist strap connected to the antistatic pad and connect the pad to a ground.

Application (Windows)

An application is a subclass computer program that is designed for end users. Examples are database, spreadsheet, and word processing programs. Applications frequently come in suites.

cd

Changes directories in the file system. For example, to change to the /home directory in the file system, you would enter cd /home at the shell prompt.

3. Identify possible causes and identify a theory of probable cause

Check for simple, obvious, and common problems first. For example, check power cords, connectors, and common user errors.

POST card

An expansion board used to troubleshoot computer system startup.

Cleaning Solutions and Solvents

Consult the MSDS, a licensed disposal organization, or local authorities for handling and authorized disposal procedures.

CRT Monitor

Contact local authorities for recycling these. CRTs contain many toxic and caustic substances that are illegal to incinerate. Also, discharge before disposal (CRTs can contain high voltages).

Power Supply

Contact local authorities. Recycle, if possible. Discharge before disposal (contains high voltages).

Control Panel

Control Panel is a compilation of various utilities that change how a computer looks and behaves. Use the Control Panel to configure settings for hardware devices, manage printers and networks, configure personal settings, and manage the system.

Dynamic RAM (DRAM)

DRAM stores data using a single transistor for every bit of data (a 0 or a 1). To maintain the state of the transistor, DRAM must continually supply power to the transistor; when the power is turned off, the data is lost. DRAM is simple to implement. DRAM can have a very high density (e.g., high storage capacity). Because of the simplicity, DRAM is relatively inexpensive. DRAM is used in the main system memory on a computer

Extension Magnet

An extension magnet is a small magnet on a collapsible rod. Use the extension magnet to retrieve screws that have fallen into a computer case or other areas you cannot reach. As an alternative to a magnet, use an extension tool with retractable prongs.

NLX

NLX (new low profile extended) is an old form factor that was designed for use in slimline desktop computers. NLX: Uses a detachable riser card to provide expansion slots (the motherboard itself has no expansion slots). Allows the motherboard to slide in or out of the system case easily. Was replaced by microATX and Mini-ITX.

Computer Cleaning

One of the best things you can do to keep your system running efficiently is to keep it clean. Be aware of the following facts about cleaning your computer: Common computer cleaning supplies include:Lint-free clothCompressed air or an air compressorSmall anti-static vacuum Denatured or isopropyl alcohol Regular cleaning gives you the chance to inspect all components. Look for worn or failed components. On electrical components, dark areas might indicate a burned-out component. Prior to cleaning computer components, power down and unplug components and let them sit for at least 30 minutes to cool. Use caution with liquid-based cleansers. Use small amounts and always apply cleaning solutions to cloths and cleaning instruments, never directly to component surfaces. Dust buildup inside a computer acts as an insulator for internal components, trapping heat and preventing adequate cooling of components. Use: Compressed air to blow dust off.A non-static vacuum to remove dust.A natural bristle paintbrush to wipe components off. Use a small amount of denatured alcohol on a cotton swab to clean electrical connectors (such as those on expansion cards). For LCD screens, use a lint-free dry cloth or a small amount of isopropyl alcohol (do not use window cleaner, ammonium-based cleaners, paper towels). You can also use special monitor-cleaning solutions or pre-packaged wipes with monitor-safe solution. For a mouse with a roller ball, clean the ball and the roller contacts on a regular basis. For keyboards, use a vacuum or compressed air. For keys that stick, use a lint-free cloth and/or cleaning swabs, lightly dampened, to gently wipe each key. To clean a printer, use a damp or dry cloth. On inkjet printers, use the printer's cleaning function to clean the print heads.For laser printers, use an anti-static vacuum to remove excess toner. A regular vacuum will build up an electrostatic charge from the toner. On removable media devices, use:Compressed air to blow dust and debris off of CD-ROM and DVD disc surfaces, out of drive bays, and off of drive heads.Soft, dry lint-free cloths to wipe smudges off of CD-ROM and DVD disc media surfaces.

Storage Devices

Devices that contain non-volatile memory for saving or maintaining data. Storage devices include: Hard disk drives Solid-state drives Optical drives (CD-ROM, DVD-ROM, and Blu-ray) Flash drives

--help

Displays a brief summary of how to use the command.

ls

Displays a list of files and subdirectories that exist within a directory. Several options are commonly used with this command: -a displays all files, including hidden files. -l displays a detailed (long) listing of directory contents including ownership, permissions, modification dates, and file sizes. -R displays the contents of the directory and all of its subdirectories.

info

Displays more extensive documentation about the command. Use the Q key to quit and go back to the shell prompt.

ifconfig

Displays the IP address and the subnet mask assigned to this system.

less

Displays the contents of a text file on the screen, pausing the output one screen at a time. For example, to view the contents of the widget.txt file one page at a time, you would enter less widget.txt at the shell prompt.

cat

Displays the contents of a text file on the screen. For example, to view the contents of the widget.txt file, you would enter cat widget.txt at the shell prompt.

head

Displays the first few lines of a text file on the screen. For example, to view the first lines of the widget.txt file, you would enter head widget.txt at the shell prompt.

Tail

Displays the last few lines of a text file on the screen. For example, to view the last lines of the widget.txt file, you would enter tail widget.txt at the shell prompt. The -f option can be used with tail to monitor a file for changes. If new content is added to the end of the file (such as a log file), the new lines will be displayed on the screen.

man

Displays the manual page for a command. It's very similar to the help screen, but it provides more detail. Use the Q key to quit and go back to the shell prompt.

pwd

Displays the path of the current directory on the screen. pwd stands for print working directory.

8. Document the solution and process

Documenting the solution and process provides you with a record of what the problem was and what you did to solve the problem. In the future, you can check your documentation to see what has changed or to help you remember the solution to common problems. It will save you time and money when troubleshooting problems.

Intermittent problems

One of the tougher detection challenges is the intermittent occurrence of error messages, crashes, or sudden reboots. The trouble in diagnosing this situation is the number of potential problems, including timing, heat, corrosion, fluctuating power, loose connections, EMI, or a combination of these problems.

Hyper-Treading

Hyper-threading is a feature of some Intel processors that allows a single processor to run threads (instructions) in parallel, as opposed to processing threads linearly. Hyper-threading enables a processor to execute two threads at the same time. For example, on a quad-core Intel system that supports hyper-threading, the processor can execute 8 threads at a time (2 on each core). Hyper-threading is not the same as multithreading. Multithreading is a feature of an application that allows it to send multiple threads at the same time. Applications are typically written to support multithreading to take advantage of multiple cores (executing threads on two or more processors at the same time) or hyper-threading features.

Force Quit

Force Quit is used to stop non-responsive processes and applications. It can also be used to restart the Finder service. Force Quit can be accessed from the Apple menu or the keyboard shortcut Command+Option+Esc.

Software

Instructions or data that are stored electronically, either on a hard drive or a special chip. Software components include the following: Operating systems. Program applications. Hardware drivers (special programs that tell the operating system how to use the hardware.)

Input

The movement of data or commands to the internal computer hardware. Input devices include: Standard input devices: Mouse Keyboard Touchscreen Gaming input devices: Game controller Joystick Media input devices: Scanner Digital camera Webcam Audio input devices: Microphone MIDI controller

Change management

The process of regulating changes to a project once it is underway.

Output

The process of the computer presenting, displaying, or otherwise giving data. Output devices include: Video Audio Printing

Laser Printer Toner Cartridges

Return to the manufacturer for recycling (to clean up spills, use a toner vacuum or a scoop and a damp cloth; never use a regular vacuum).

File Types

Sound card drivers and other software save digital audio into several different file types. Common file types include: WAV (Windows standard), a widely used and compatible file type AIFF (Audio Interchange File Format), the Macintosh equivalent of the WAV AU (UNIX standard), supported by most web browsers MP3 (MPEG-2 Layer III), a highly effective audio compression standard AAC (Advanced Audio Coding), also known as MPEG-2, a compression expected to replace MP3 WMA (Windows Media Audio), a highly compatible standard developed to compete with Real Audio MIDI, not a true audio file, but contains data to reproduce sounds through electronic synthesis

Bus Support

Sound cards can be installed via an expansion slot (e.g., PCI or PCIe x1) on the motherboard. When selecting a sound card, make sure the bus type is compatible with your motherboard. Most new motherboards have an onboard sound card.

Spotlight

Spotlight is an indexing utility that can perform system-wide searches to locate folders, files, apps, and internet results that contain the specified search phrase. Spotlight is access pressing Command(⌘)+Spacebar or by selecting the Spotlight icon on the Status menu.

4-pin 12 V (P4) power

Starting with the Pentium 4 (P4) processor, CPUs required more power than could be provided through the ATX power plug. The 4-pin 12 V connector: Connects to the motherboard Provides two dedicated 12 V wires to the CPU (Older processors only used 5 V power) The 4-pin 12 V CPU connector is not the same as the 20+4-pin ATX power connector.

bash

Starts a new Bourne-again shell (bash) session.

4-pin mini-Molex

The 4-pin mini-Molex connector provides both 5 and 12 volts and is used by floppy drives. Most modern power supplies do not have a 4-pin mini-Molex connector.

Multitasking

The ability to run multiple applications simultaneously.

Multithreading

The ability to run multiple parts of an application simultaneously.

Multiprocessing

The ability to use multiple processing devices.

Command Key (Apple)

The Command (⌘) key is the primary modifier key on Apple systems. For example, Command+C copies the selected item to the clipboard, and Command+V pastes the contents of the Clipboard. When used in a Boot Camp Windows installation, the Command key serves the same function as the Windows key.

UniDIMM

UniDIMM (Universal DIMM) is a specification for DIMMs and is designed to carry DRAM chips. UniDIMMs can be populated with either DDR3 or DDR4 chips, but do not support any additional memory control logic. Because of this, the computer's memory controller must support both DDR3 and DDR4 memory standards. UniDIMM: Is an upgrade to the current SODIMM standard Allows mobile platform users to use both DDR3 and DDR4

USB

Universal Serial Bus The USB port is one of the most common computer ports. USB ports are used to connect a variety of devices. Mouse and keyboard devices External storage devices Digital cameras Printers Scanners Microphones Webcams

Process Size

The process size refers to the manufacturing process used to etch transistors onto the silicon wafer that will become the CPU. A smaller process size means smaller transistors, which translates into a smaller CPU die with more transistors and less power consumption. Process size is expressed in microns (such as .25 microns) or nanometers (90 nm which equals .09 microns).

Heating, ventilation, and air conditioning (HVAC)

The system installed within buildings to control temperature by supplying heat and air conditioning.

Taskbar

The taskbar is the bar displayed at the bottom of a Windows desktop (although its position can be changed). The taskbar: Contains icons that represent each program or application currently running or pinned to the taskbar for quick access. You launch a pinned program by selecting the icon on the taskbar. Can be configured to display different types of toolbars. For instance, Quick Launch is a toolbar that contains shortcuts to designated programs.

AC (alternating current)

The type of current distributed through wall sockets.

DC (direct current)

The type of current used inside a computer.

VGA (DE-15)

The video graphics array (VGA) port is used to connect external display devices such as projectors and some monitors. VGA ports: Transmit an analog video signal. Have three rows of five pins. Use a DE-15 connector.

Utilities (Windows)

Utilities are the features or programs included with an operating system that perform system-related tasks. Common Windows utilities are Control Panel and This PC. Common Linux utilities are cd, cp, grep, and Is.

microATX Tower

microATX towers are smaller cases designed to be placed on desktops. microATX towers typically have only one drive bay and are compatible with the following form factors: microATX Mini-ITX Some microATX towers have a slim design. These cases are typically half the width of a microATX tower and are designed to lie flat or upright.

Professionalism Facts

As a PC technician, it is important to always act in a professional manner. Being professional will not only optimize the client's experience, but also dispel the myth that PC technicians have poor people skills. Consider the following guidelines when interacting with clients: Make a good first impression. If your first contact with the client is positive, the relationship will be much easier to handle and maintain.Arrive to appointments on time and prepared. If you are going to be late, contact the client and let them know.Dress professionally and following any company dress codes. This includes appearing well-groomed.Greet the client and introduce yourself.Ask permission before entering the client's office or home.Address the client using the appropriate title.Be sensitive to cultural differences between the two of you. Communicate effectively. Understanding both your and your client's expectations is very helpful.Use clear, concise, and direct statements.Ask the client open-ended questions so the client will talk about the issue and you can gather information.Allow the client to speak and avoid interrupting.Clarify client statements—restate what the client said and ask pertinent questions.Take notes on complicated or important information.Avoid using jargon, abbreviations, and acronyms. Take time to explain technical terms and issues in a simple way.Clearly explain the problem and any repair options. Be sure to explain the advantages, disadvantages, and cost of a repair.Set realistic expectations for finishing work—when in doubt, overestimate. Show respect. This includes showing respect not only to your clients, but also their workspaces and computers.Never argue with a client or become defensive.Avoid accusing the client. Even if the client caused the problem, do not point fingers.Ask before moving items on desks or making changes to computer systems.Stay calm and avoid being judgmental or insulting.Avoid distractions or interruptions, including texting and social media notifications. Don't take personal phone calls. Ask permission before taking work-related calls.Do not browse files on computers that are not necessary or related to the repair.Never complain about clients on social media platforms. Being professional extends to identifying the problem and implementing solutions. During this process, keep in mind the following: Get authorization to proceed before making any unexpected repairs or fixing items that were not part of the original problem, especially if the extra repairs result in an additional charge. After you have fixed the problem, try it out (or let the client try it out) to make sure that other problems don't exist. After the repairs are finished, provide the client with a detailed invoice of the work performed. Also include any manuals or documentation related to new hardware. Ask the client if they would like to keep the failed components. If necessary, take the time to briefly explain any new software or hardware that was installed. If applicable, offer additional services or training that might be beneficial to the client. If the problem is related to user error or is caused by actions taken by the client, tactfully explain the problem without accusing or judging the client. Before leaving, make sure the client is satisfied that the problem has been resolved. For best client service and based on your company policy, follow up with the client at a later time to verify that the problem remains fixed. If a request is outside of your ability or responsibility, help the client get in contact with the appropriate resources, such as another technician or an authorized manager.

Windows Basics

As you study this section, answer the following questions: What are the kernel's functions? What is the difference between a GUI and a CLI? What type of information is shown on the taskbar? Which Windows interface components would you use to switch from one running program to another? How does an index improve searching on your computer?

Channels

Audio can be split into multiple channels, which increases the sound quality and makes it more realistic. Some standard channel configurations are as follows: 2 channel audio is stereo. Examples of 2 channel audio include standard TV and radio. 4 channel audio is quadraphonic audio and was an early attempt at surround sound. 5.1 channel audio, also known as surround sound, has 6 audio channels: five speakers and one low-frequency effects subwoofer (LFE) channel. 7.1 channel has 8 audio channels: 7 speakers and one LFE subwoofer channel. This is the first technology providing error correction.

Audio Jack

Audio jacks are used to send or receive analog audio signals. Audio jacks use 3.5 mm TRS connectors to connect audio devices such as: Speakers Headphones Microphones Audio output devices Audio jacks use a common color code to denote the port type: Green: line out Pink: mic in Blue: line in Orange: subwoofer Black: rear speakers

Heat sink

Heat sinks are made of a heat conductive material (usually aluminum or copper) and are attached to components using a thermal paste or pad. Heat sinks are designed with fins to increase the surface area exposed to air, allowing heat to dissipate from the component much faster. Heat sinks can be either active or passive. Active heat sinks have an attached fan that helps cool off the component at a faster rate. Active heat sinks are used with the following components:CPUsHigh-end video cardsSome motherboard chipsets with integrated graphics Passive heat sinks do not have a fan and instead rely on increased surface area and passive air movement to cool the component. Passive heat sinks are used with the following components:Most motherboard chipsetsLow-end video cardsMemory modules (heat sinks on memory modules are also called heat spreaders) Because passive heat sinks do not use a fan, they are 100% reliable. However, active heat sinks can dissipate heat much faster than passive ones.

HFS

Hierarchical File System.

HTPC

Home theatre PC (HTPC) cases are designed to connect to TVs and be used as a home media computer. HTPC cases are compatible with microATX and Mini-ITX form factors.

CPU socket

Houses the CPU.

32-Bit or 64-Bit

A 32-bit processor can process 32-bits of information at a time; a 64-bit processor can process 64-bits of information. The biggest advantage of 64-bit processors over 32-bit processors is in the amount of memory they can use. 32-bit processors have a limit of 4GB. 64-bit processors have a theoretical limit of 16 EB, although operating system and current hardware limitations impose a much lower practical limit. The operating system and applications must be written for 64-bits to take full advantage of 64-bit processing. The processor instruction set identifies all instructions (operations) that a processor can perform.32-bit processors use the IA-32 instruction set (also referred to as x86).Itanium processors from Intel use the IA-64 instruction set.AMD64 and Intel 64 processors use the x86-64 instruction set (also referred to as x64). 32-bit applications can run on 64-bit processors using the following methods:Itanium processors use a software layer to translate between IA-32 and IA-64.x64 processors execute both 32-bit and 64-bit instructions in the hardware.You can run a 32-bit operating system on a computer with a 64-bit processor. Applications typically perform better on 64-bit systems.64-bit applications typically perform better than 32-bit applications.In some cases, 32-bit applications might perform better on 64-bit systems.

DDR DIMM

A DIMM (dual in-line memory module) has pins on both sides of the module, with each pin being unique.DIMMs have a 64-bit data path that matches the system bus width.RDRAM and DDR/2/3/4 are packaged into DIMMs, with each specification having a unique number of pins and notch position.DDR4 allows for DIMMs of up to 512 GB in capacity.

TOSLINK

A TOSLINK (or optical audio cable) connector is used with digital optical I/O for S/PDIF audio.

Cable Tester

A cable tester verifies that a network can carry a signal from one end to the other and that all wires within the connector are in the correct positions. Most testers have a single unit that tests both ends of the cable at once. Many testers come with a second unit that you can plug into one end of a long cable run to test the entire cable.

Motherboard

A circuit board that either houses or is connected to all of the components operating in the computer.

Missing BIOS/UEFI Settings Problem

A constant source of power is required to store the settings configured in the motherboard BIOS/UEFI chipset. The motherboard also needs constant power to keep the system clock running while the system is powered off. Most motherboards implement a small battery that provides this power. If this battery starts to fail, then the following may occur when the system is powered on: The system clock loses time. Settings configured in BIOS/UEFI are lost. If this happens, it's likely that the motherboard battery has failed and needs to be replaced.

Distribution

A custom version of Linux.

Loopback Plug

A loopback plug is used to test network communications by redirecting a signal from the transmit port on a device to the receive port on the same device. Use the loopback plug to verify that a device can both send and receive signals.

Boot Errors

A malfunctioning motherboard may generate error codes when the system is powered on. Every time the PC boots, it runs a Power On Self-Test (POST) to make sure all of the basic hardware in the system is present and functioning correctly. If a problem is identified during POST, an error is generated. How the error message is reported to the end user depends upon the motherboard manufacturer. The following may be used: Audible beeps Numeric codes Error messages The actual codes and messages will vary by manufacturer. Check the motherboard documentation for specific details. For example, a numeric 201 error code may indicate a memory problem on some systems, while a 301 error indicates the keyboard did not respond correctly during POST. Sometimes, a computer system may experience problems (such as a malfunctioning video adapter) that can prevent error messages from being displayed during POST. If this is the case, use a POST card to access POST error codes. Most models use an LED display to report any error codes generated during POST. A POST card is commonly implemented as an expansion board that is inserted into an expansion slot in the motherboard. However, some POST cards also include a USB interface that allows them to be connected to computers that don't have expansion slots, such as a notebook system.

Electromagnetic interference (EMI)

A signal caused by motors, heavy machinery, and fluorescent lights that interferes with wired networking signals.

Extension magnet

A small magnet on a collapsible rod used to retrieve parts that fall into a computer case or another area that hands cannot reach.

Three-pronged parts retriever

A small tool used to grasp and retrieve small parts that fall into places difficult to reach with hands.

Loopback plug

A small tool used to test network communications.

HDMI

A sound card with an HDMI port is capable of sending HD audio to an HDMI device. Some sound cards are able to output video or combine a video signal from a video card and output the combined audio/video signal through the HDMI port.

ATX Full-tower

ATX full-tower cases are the largest computer cases. Full-tower cases have a lot of space for external and internal components. ATX full-tower cases are compatible with the following form factors: Standard ATX EATX microATX

ATX Mid-tower

ATX mid-tower cases are slightly smaller than full-tower cases. Mid-tower cases have fewer external and internal bays. ATX mid-tower cases are compatible with the following form factors: Standard ATX microATX Mini-ITX EATX (some)

Power supply

ATX power supplies aid in cooling by exhausting hot air out the back of the case.

Feature Support

Additional features on sound cards provide higher quality sound or additional functionality. DirectSound 3D allows a computer to play audio in surround sound. EAX is a high-definition sound technology originally developed for video games. This technology provides such realistic nuances that audio can actually cue gamers. THX is a sound quality standard, originally created for film, now available on sound cards. This is a sound card feature that allows computers to present theater quality sound output. Dolby Digital is a technology that broadcasts sound at a frequency the human ear can hear and diminishes collateral sound. This is a sound card feature that allows computers to present higher quality sound output. DTS (Digital Theater Systems) Digital requires an optical reader to decode physical data and send it to a computer for processing. This is a sound card feature that allows computers to present theater quality sound output. SDDS (Sony Dynamic Digital Sound) was originally developed for theater sound. SDDS decoders provide error correction. MIDI (Musical Instrument Digital Interface) is a protocol for recording and playing audio created on digital synthesizers. This feature allows the computer to become an integrated component to a musical instrument.

Aero

Aero is a set of features that improves the visual appearance of Windows. Features of Aero include: Glass effects on window borders that make borders semi-transparent (translucent). You can view objects behind windows through the window borders. Window animations when windows are opened or closed. Taskbar thumbnails that show the contents of an open window when you move the mouse over items on the taskbar. Windows Flip shows thumbnails of running programs when you use the Alt + Tab keys to switch between running programs. Aero Flip 3D is activated with the + Tab key and shows an expanded 3D view of running programs. The Show Desktop button (on the right side of the taskbar) hides all open windows. Hovering over the button makes the content of all open windows disappear (called Peek). Snap is a new feature that maximizes a window as you drag its border to the edge of the screen. Snapping multiple windows on the screen tiles them side-by-side. In Windows 10, Snap is limited to four apps on the desktop and two apps on a tablet. Shake lets you hide all but the current window. Select the top window border and shake the mouse to hide or unhide all other open windows. Aero is not available in the Windows 7 Home Basic version. In addition, features depend on the graphics card in the system. For example, you might not be able to use Flip 3D if the graphics card does not have the necessary features.

Interface (Windows)

An interface is what allows the user to interact with the kernel and the utilities. There are two main types of interfaces, command line and GUI. In command line interfaces, commands are executed through instructions written into a command line. Examples of command line-based interfaces are MS-DOS and aspects of Linux. In a Graphical User Interface (GUI), the user executes commands by clicking on graphics and symbols. Windows is an example of graphical user interface.

Standby power supply (SPS)

An offline devices that provides power when an under-voltage occurs.

Linux

An open source operating system.

Windows Operating System Facts

An operating system is a set of programs that acts as an interface between the applications that are running on a computer and the computer's hardware. Operating systems perform actions such as: Receiving user input from input hardware devices such as the keyboard or mouse Sending user output to output hardware devices such as the monitor or a printer Controlling the use of processing devices by applications Serving as a platform for applications Moderating hardware Providing security Managing the file system Some operating systems also have attributes such as the following: Multiprocessing is the ability to use multiple processing devices. Multitasking is the ability to run multiple applications simultaneously. Two common variations are:Cooperative multitasking means that multiple processes must work together for the operating system to work effectively.Preemptive multitasking forces applications to share the CPU. Multithreading is the ability to run multiple parts of an application simultaneously.

Spike

An over-voltage that lasts milliseconds.

Surge

An over-voltage that lasts seconds.

Sag

An under-voltage that lasts milliseconds.

Brownout

An under-voltage that lasts seconds.

Uninterruptible Power Supply (UPS)

An uninterruptible power supply is an online device that is constantly providing battery power to the computer and being recharged by the wall outlet. There are two types of UPS systems: An online UPS constantly powers the computer from the battery.An offline UPS powers the computer from the wall power. When the power fails, a switch inside the UPS switches to power the computer from the battery. This is the most common form of UPS. UPS size is measured by the volt-amp (VA) rating. The capacity of the UPS determines the number of devices and how long the devices can run when power is interrupted. When purchasing a UPS, purchase one with enough battery power to power only critical devices such as the computer and a single monitor.To reduce the amount of power required by the UPS, do not plug non-critical devices in to the UPS.Laser printers require more power than most UPS systems are capable of providing. For this reason, you should not connect a laser printer to a UPS. If you must provide power to a laser printer, get a dedicated UPS for that device. A UPS is designed to provide enough power to shut a system down safely during an extended power outage. Most are not intended as long-term power solutions. The UPS connects to the power source (usually a wall socket), the computer plugs into the UPS, and the UPS is connected through a serial or USB port to the computer. Software on the computer uses this connection to monitor battery life and to detect when the regular power is lost. You can configure the software to shut the system down automatically when the battery charge reaches a certain level. You usually need to configure the following settings when working with UPS software:Time to wait before sending a warning to clientsTime to wait before beginning a shutdownName of programs or commands to run during shutdown In addition to providing power when the power is lost, most UPS systems also condition the line and remove power spikes and sags. Most UPS devices sound an alarm when the AC power is lost. This alarm continues until AC power is restored, although many UPS devices have a switch to mute the alarm.

Analog Input and Output

Analog output jacks allow you to play sound on your computer through external devices: The speaker out connector sends signal to external speakers. This signal is amplified and the computer controls the sound level that is sent. The line out connectors send audio to other sound devices. This signal is unamplified. Analog input jacks allow you to record audio through the sound card. The line-level (line-in) connector receives signals from CD players and musical instruments coming from the line out port of the other device. The mic-level (mic in) connector receives signals from a microphone.

CAS Latency

Another factor that affects the performance of memory is the latency associated with accessing data in RAM. With a read request, there is a delay between the time the data is requested and the time that the data is available on the module's output pins. This delay is called the CAS latency (CL). Older memory expressed the delay in nanoseconds, but DRAM uses a ratio based on the clock frequency to describe the delay. For memory modules of the same type and frequency, a lower CAS number indicates less delay (e.g., "faster" RAM). Because CL is related to the frequency, you cannot directly compare the CAS latency between modules with a different frequency. For example, a DDR2 module operating at 533 MHz with a CL of 6 has more delay than a DDR3 module at 667 MHz with a CL of 7. In addition to CL, there are other memory characteristics that describe the delay for performing other types of operations. Collectively, these values are referred to as the memory timings. For stable operations, the bus must take into account these latencies to keep the bus and the memory synchronized. Manufacturers test memory modules and rate them based on the operating frequency and the timing characteristics. Settings that produce stable performance are then encoded into the SPD module on the memory. The BIOS then reads this information to know how to configure memory settings on the motherboard. For many systems, you can manually modify the memory timings and frequency. Running RAM at a lower clock speed enables you to decrease the CAS latency setting; increasing the frequency must usually be compensated for by increasing the CL (and other) settings.

Management Tips

Be aware of the following tips for maintaining your computer: When receiving a new computer or component that has been shipped, let it sit for at least six hours (24 hours if it arrives in outside freezing conditions) before applying power. The rapid change in temperature can cause damage to components or can result in condensation within the computer. Perform regular backups. Backups protect your data if a hard disk fails. You can use covers and cases to protect some equipment from dust and liquid spills. Be sure to remove covers before use and replace after use. Keep cables organized. Route cables to prevent them from being kinked or stepped on. For best results, use cable ties to bind and organize cables. Verify that your system's cooling fans are blowing air through the system case in the correct directions. A fan blowing in the wrong direction can negate the airflow through the case and cause the system to overheat.

Configure the System Sound

Be aware of the following when configuring system sound: Many motherboards include an onboard sound card. Use the connectors on the motherboard's I/O plate to connect components to the onboard sound card. Sound cards are typically added to a computer using PCI or PCIe slots. Some sound cards also connect through USB. External sound cards for laptops can use an ExpressCard slot. When installing a sound card using an expansion slot, make sure to disable the onboard sound card in the CMOS configuration. After installing the sound card, install the drivers and other software that came with the sound card. In Control Panel, use the Sound applet to:Configure settings for sound card connections such as speakers, audio input, and microphone.Identify the sources that you want to record.Configure sounds to play with system events or to play a sound to test your configuration. An audio codec is a specific method of formatting sound files. Common codecs include WAV, WMV, AIFF, and MP3. To play sounds saved using these formats, your computer must have the corresponding codec installed.You can see the list of installed codecs in System Information.By default, Windows comes with common codecs installed. Other codecs might be installed as you add other software.

Lifting

Be careful when lifting heavy objects. Bend your knees and keep your back straight, using your legs to lift objects. Wear a back brace for added protection if your job requires frequent lifting. Use carts and other tools when moving heavy objects for any significant distance. Ask for help, if necessary, when lifting or moving heavier objects. Follow the weight limitation guidelines defined by your employer.

Capacitor (Safety)

Be sure to discharge capacitors or turn the equipment over to qualified personnel for servicing. Similarly, exercise caution when working with the DC converter in a laptop display.

Remote Disc

Because many modern Apple devices are being manufactured without a CD or DVD installed, Mac OS offers the Remote Disc feature. With Remote Disc: The CD or DVD can be shared on the network. Devices on the same network can access the shared remote CD or DVD. Only data CDs and DVDs can be accessed. Media discs such as audio CDs, Blu-ray and DVD movies, or installation discs cannot be accessed remotely.

Cooling System Recommendations

Because proper airflow is necessary to keep components cool, consider the following recommendations to ensure optimal system cooling: Keep the case free of dust and debris. Excess dust can restrict airflow and prevent proper heat transfer. Reduce the number of airflow obstructions.Employ proper cable management (e.g., bundle cables together and secure unused cables to the case).Space out multiple hard disk drives instead of stacking them next to each other.Do not use an excess number of expansion cards. Maintain appropriate ambient temperatures. Optimal ambient temperatures are between 60 and 80 degrees Fahrenheit. For server rooms, the ambient temperature might be as low as 45 degrees. Ensure proper ventilation.Keep air intakes and exhausts free from obstructions.Leave space between the computer and any walls or desks. Preserve negative pressure inside the case by keeping all covers and shields installed (e.g., unused expansion cards, I/O shield, front drive bays).

Boot Camp

Boot Camp is a Mac OS feature that allows an Apple device to install the Microsoft Windows OS. Boot Camp makes installing Windows a very simple process by using the Boot Camp Assistant app. The Boot Camp Assistant: Automatically creates a BOOTCAMP partition on the hard drive and prepares it for installing Windows. Reboots the system and starts the Windows install process from the selected installation media. Creates a Boot Camp system tray icon in both Mac OS and the Windows installation to switch between the Windows and Mac OS installation. Boot Camp has the following system requirements: Intel-based Mac Installation media containing 64-bit version of Windows 8 or later 55 GB of free space

Buffered (Registered)

Buffered (or registered) RAM has a buffer that holds memory addresses or data before it is transferred to the memory controller. Buffered RAM improves stability on systems with a lot of RAM (over 1 GB). Buffered RAM might slow system performance. ECC modules are typically buffered. Buffered RAM must be supported by the motherboard. Some motherboards require buffered memory. Unbuffered memory does not have a buffer to hold memory addresses or data before it is transferred to the memory controller. Unbuffered memory is used in common workstations and laptops. Buffered memory is used in servers and high-end workstations.

Legacy buses

Buses that have been replaced by newer types are considered legacy buses. Legacy buses are rarely used and include the following: AGP (accelerated graphics port) was a dedicated bus type used by dedicated video cards. AMR (audio/modem riser) was a riser card that attached to the motherboard and allowed additional cards (called daughter cards) to be installed. CNR (communications network riser) was a riser card slot that allowed for installing network, sound, or modem functions.

Complementary Metal-Oxide Semiconductor (CMOS)

CMOS is legacy computer chip technology that has become a general term used for the program that stores important system information related to the starting of a computer. It is often used synonymously with BIOS. Data held in CMOS includes the hard disk type and configuration, the order of boot devices, and other configurable settings related to the system hardware. The following are important things to know about CMOS: You changed the data stored in CMOS using a CMOS editor program that was part of the BIOS. CMOS used to refer to the real-time clock and the CMOS chip that stored system information. Both were powered by a CMOS battery. Now, the EEPROM chip stores the system information that used to be stored on the CMOS chip. EEPROM requires no power to maintain data storage. The CMOS battery is still used to keep the real-time system clock running when the computer is powered off. It can be a low-voltage dry cell, lithium mounted on the motherboard, or even AA batteries in a housing clipped on a wall inside of the case. The electric current is about 1 millionth of an amp and can provide effective power for years.

Cache

Cache is memory that the processor can access directly without using the system RAM. There are four types of processor cache: Level 1 (L1) cache is integrated on the processor die itself and stores instructions for the processor. On multi-core systems, each processor typically has its own L1 cache. Some processors might have two L1 caches, one for instructions and one for data. Level 2 (L2) cache is additional cache used for both instructions and data. Depending on the processor, L2 cache might be shared between two or more cores, or exclusive to a single core. Level 3 (L3) cache is additional cache beyond the level 2 cache. For multi-core systems, L3 cache is shared between all cores. Level 4 (L4) cache is shared dynamically between the on-die graphics processor unit (GPU) and CPU. Be aware of the following regarding processor cache: The size of the cache increases as you move from L1 to L4, with L1 cache being the smallest. As a general rule, a processor with more cache performs better than a processor with less cache (all other things being equal). Originally, only L1 cache was on the processor die, with L2 cache being on the motherboard between the CPU and the RAM. As processor technology has advanced, L2 cache moved to the processor die, with L3 cache being on the motherboard. Today, all three cache levels are located on the processor. The L4 cache acts an overflow cache for the L3. Information evicted from L3 is dumped into L4.

Cleanliness

Clean hardware regularly to avoid problems caused by built-up dust. Use compressed air to clean delicate components. Use a specialized vacuum to clean dust from other hardware. Avoid blowing dust into other hardware or all over your office.

Blackout

Complete power failure.

Modern hardware components use modular design that implements both componentization and standardization.

Componentization: a functional PC is a combination of several constituent parts. Each part is considered a field-replaceable unit (FRU), meaning it can be quickly replaced when faulty or easily upgraded when needed. Componentization keeps maintenance costs low and reduces downtime. Standardization: specifications that allow components from different manufacturers to be interchangeable. If a component meets the specified standards, it will work in the computer regardless of manufacturer.

Thermal

Components such as the CPU heat sink and fan, the printing head of a dot matrix printer, or components inside a laser printer can be hot. After turning off a computer or printer, allow components to cool sufficiently before servicing to prevent burns.

Power supplies are responsible for powering every component in a computer system. Power supplies perform the following functions:

Convert AC power to DC powerAC (alternating current) is the type of current distributed through wall sockets. The voltage alternates between a negative and a positive charge, which is good for appliances requiring a high current.DC (direct current) is the type of current used inside a computer. Negative particles are drawn toward a positive charge, creating a unidirectional current flow. This type of predictable reliable current is ideal for an application where a lower current is required. Provide components with the correct levels of DC voltageStandard ATX power supplies provide + 3.3 volts, +/- 5 volts, and +/- 12 volts of DC power. Most modern components require +12 volt output.Each separate voltage output circuit is referred to as a rail and can power multiple devices. To avoid overloading one circuit, many newer power supplies have two or more +12 volt rails. These are known as dual rail power supplies. Separate rails balance the power load between multiple circuits, preventing any one circuit from becoming overloaded. Aid in thermal managementAll ATX power supplies have a fan that cools the unit.The fan direction pulls cooler air from the front of the case and blows hot air out the back.Older ATX units use a reverse air flow that blows air directly over the CPU. This method is not as efficient.

Cp

Copies files and directories from one location in the file system to another. For example, to copy the widget.odt file to the /home/rtracy directory, you would enter cp widget.odt /home/rtracy at the shell prompt. To copy an entire directory structure, include the -R option, which specifies that the directory contents be recursively copied.

Features new to Windows 10 include:

Customizable Start lets you organize your apps and shortcuts. Microsoft Store allows you to purchase music, videos, games, and apps Cortana provides you with a personal assistant for web searching. This feature is only available in the United States, United Kingdom, China, France, Italy, Germany, and Spain. This feature is hardware-dependent. Microsoft Edge lets you write and highlight web pages in the Edge web browser. This feature is hardware-dependent. Windows Hello uses face and fingerprint sign in. This feature is hardware-dependent. Photos app organizes photos and videos in one location. Cloud storage provides integrated access to OneDrive, which provides free storage space in the cloud. Continuum allows you to switch between PC, tablet, and phones modes. This feature is hardware-dependent.

DDR

DDR (Double-Data Rate Synchronous Dynamic RAM) is a variation of the original synchronous DRAM (SDRAM). All variations of DDR are synchronized with the system clock and accept 64-bit words. DDR accepts a single command and two consecutive data sets per bus clock cycle. Operating at the same frequency, DDR has twice the bandwidth of SDRAM. DDR operates at 2.5 volts at bus frequencies between 100-200 MHz. DDR memory has a single notch, slightly off center. DDR memory has 184 pins.

DDR2

DDR2 doubles the data transfer rate of DDR, for four times the bandwidth of SDRAM. DDR2 accepts four consecutive 64-bit words per bus clock cycle. DDR2 includes a buffer between the data bus and the memory. DDR2 operates at 1.8 volts at bus frequencies between 200-533 MHz. The internal memory frequency is half that of the bus frequency (100-266 MHz). DDR2 memory differs from DDR memory as follows: The notch is slightly closer to the middle. It has 240 pins. While you don't need to count the pins, you should notice that the pins are smaller because they have to fit in the same space as the DDR memory.

DDR4

DDR4 doubles the data transfer rate of DDR3 for ten times the bandwidth of SDRAM. DDR4 accepts eight consecutive 64-bit words per bus clock cycle. DDR4 operates at 1.2 volts at bus frequencies between 1066-2133 MHz. The internal memory frequency is about one-tenth that of the bus frequency (100-266 MHz). DDR4 reduces the demand for power. DDR4 is not compatible with earlier types of random access memory (RAM) because of the different signaling voltages, physical interface, and other factors. DDR4 theoretically allows for DIMMs of up to 512 GB in capacity, compared to the DDR3's theoretical maximum of 128 GB per DIMM. DDR4 memory has a single notch slightly right of center. DDR4 has 288 pins.

Scope (Change Order Form)

Define exactly what you wish to change and, if helpful, what you don't wish to change.

rm

Deletes files and directories from the file system. For example, to delete the widget.odt file, you would enter rm widget.odt at the shell prompt.

vi

Edits the contents of a text file. The vi uses four different operating modes: Command mode Command-line mode Insert mode Replace mode For example, to edit the contents of the widget.txt file, you would enter vi widget.txt at the shell prompt. You would then press the i key to enter Insert mode and make the necessary changes to the file. When done editing the file, you would press the Esc key to enter Command mode. Then you would press the : key to enter command-line mode where you would enter exit or wq (for write and quit) to save your changes and exit the vi editor.

The system boots, but the display remains blank

Either a card or memory module is not seated, or the system includes unsupported memory. Non-parity RAM is incompatible with ECC memory and SDRAM is incompatible with EDO memory.

The system boot fails and sounds a beep code

Either no memory is installed or the memory was not detected.

Error Correcting Code

Error Correcting Code (ECC) memory is a type of memory that detects and corrects the common kinds of internal data corruption. ECC memory is also called parity memory. Using ECC, a value is appended to the end of each byte so that the value of the data can be compared and recalculated if an error occurs. ECC is an improvement on parity techniques because errors in more than one bit can be detected and corrected. Keep in mind the following facts about error correcting memory: Memory modules with ECC have extra memory chips on the module (typically 9 modules instead of 8). If the number of chips is divisible by 3 or 5, the module is ECC memory. ECC or parity memory must be supported by the motherboard. Because it is more expensive than non-ECC, ECC memory is typically used only in servers. ECC memory is slower than non-ECC memory. Do not mix ECC and non-ECC memory in a system. Mixing ECC and non-ECC memory disables the error correction function. You might hear the terms parity and ECC being used interchangeably. However, parity RAM only checks for errors while ECC RAM checks and corrects errors.

Fire

Every room in which you work should be fire suppressed. Have at least a Class C fire extinguisher available. A Class C fire extinguisher is made for electrical fires. Make sure fire extinguishers and fire suppression methods (e.g., sprinklers) are properly implemented and maintained. Promptly report any potentially hazardous situations. Make the safety of others your top priority in responding to any incident. In the event of a hazardous situation, clear people from the area or remove the danger before attempting other actions such as preventing or repairing damage to components.

ESD and High Voltage

Exercise great care when working with electricity. Use ESD wrist straps not only protect components, but to reduce the chance of accidental electrical shock. Properly ground yourself before working with components. Do not use an ESD wrist strap when working with monitors, power supplies, laptop LCD panels, or other high-voltage components. Exercise caution when wearing jewelry, because it readily conducts electricity and could cause burns or even electrocution.

Expansion Bus Types

Expansion cards are used to expand a computer's functionality or increase its performance. Expansion cards are installed into the expansion slot on a motherboard. Expansion cards and slots use different expansion bus standards that define communication specifications as well as physical characteristics. The following table describes the characteristics of the most common expansion bus types:

Expansion Slots

Expansion slots (also called expansion buses) allow you to expand the capabilities of your computer by installing expansion cards. There are a number of different expansion slot types: PCI (Peripheral Component Interconnect) PCI-X (Peripheral Component Interconnect Extended) PCIe (Peripheral Component Interconnect Express) Accelerated Graphics Port (AGP)

CPU Performance Facts

For a long time, processor clock speed was used as a measure of processor performance. This is not necessarily true for newer processors for the following reasons: If two processors are of the same type, higher speed typically means higher performance. With processors of different types, speeds might not be comparable. It is important to make sure your motherboard can support the speed of your processor. Many processors use a performance rating, instead of speed. A higher number indicates a better-performing processor. However, performance ratings are typically applicable only between models of the same manufacturer. In some cases, buying a processor with double the cache can nearly double the performance. Dual core processors offer better performance, but typically not double. Software must be specially written to take best advantage of the dual core processors. Special instruction sets supported by a processor can increase performance. For example, hyper-threading support on Intel processors can boost performance for specific types of operations. Performance can also be increased by modifying other system components such as adding more RAM, using a faster disk, or improving cooling and ventilation. Overclocking is a feature that causes the processor to operate at a higher speed. Overclocking is typically performed by those who want to get the maximum performance from their systems. Some important things to know about overclocking are:Overclocking can cause system instability, component damage, and can void your warranty.Motherboard bus, processor, and memory settings should be adjusted to match the overclock speed.Overclocking may require more voltage.Overclocking often increases heat output. For this reason, it may be necessary to upgrade your cooling devices.

Heating, Ventilation, and Air Conditioning (HVAC)

For computer components, design HVAC systems with the following in mind: Keep temperature between 70 and 74 degrees to prevent components from overheating. Keep humidity between 40 and 70 percent to prevent electrostatic discharge (ESD). Make sure server rooms have separate ducting or HVAC systems from the rest of the building for better temperature control. Use positive pressure systems. Positive pressure systems protect the air quality in the facility by causing air to be forced out through doors, windows, and other openings. Negative pressure systems draw air in, potentially bringing in airborne particles such as dust or smoke. Positive pressure systems are more energy effective. In areas with heavy smoke or dust, add filters to air intake systems to filter out airborne particulates.

Frequency

For optimal performance, you should match the memory frequency (sometimes called the speed) with the frequency supported by the system bus/memory controller. You can install slower memory in the motherboard, but this will degrade performance. You can install faster memory in the motherboard, but it will operate only up to the maximum supported by the motherboard. When you mix memory with different frequencies, all memory will operate at the lowest frequency. Most memory modules include an EEPROM chip that identifies its frequency. The BIOS uses the information in this chip to set the frequency automatically. On many systems, you can edit the BIOS manually to change the frequency. If the BIOS does not configure memory to run at its highest rated speed, then do the following:Verify that the motherboard supports that speed. You might be able to update the BIOS to support faster memory.The serial presence detect (SPD) on the memory is often set below the maximum rating for the memory. To use the maximum speed settings, you might need to manually configure the speed and timing settings for the memory (if the motherboard allows you to do this).

Gestures

Gestures are specific finger motions that are used to perform a specific function on a Mac OS system. They are used by Apple systems that use an Apple Multi-Touch trackpad, a Magic Mouse, or a touchscreen. Below are just some of the gestures that are available on Mac OS: Right-click: Tap with two fingers to right-click. Smart zoom: Double-tap with two fingers to zoom in on a web page, image, or document (double-tap again to zoom out). Scroll: Slide up or down using two fingers to scroll up or down. Zoom: Spread two fingers apart to zoom in. Bring fingers back together to zoom out. Page navigation: Slide two fingers left or right to navigate between pages in a document. Mission Control: Slide four fingers straight up to open Mission Control. All apps: Slide four fingers straight down to display all windows of the active app.

I/O Connectors

I/O connectors for onboard components are located on the back of the motherboard. These connectors typically include the following: PS/2 mouse and keyboard ports USB ports Serial ports (COM 1, 2, 3, and 4) Parallel port Audio jacks Ethernet port An I/O shield fits over the connectors to secure them and protect the inside of the computer from dust and debris.

Risk Analysis

Identify risks associated with the change. For example, allocating additional funding to the project may strain another project's budget. Adding a new member to a team may negatively impact the team's effectiveness as training the new member will cause stress and consume time. Explain why the risks you identify are worth taking, and present a plan for mitigating risks and avoiding problems.

Smoke or Burning Smell

If smoke or a burning smell is observed coming from a computer, it indicates that electricity is not flowing in the correct manner within the system. If smoke is observed, shut the system off immediately. This issue could be caused by: A connector that isn't seated properly and electricity is arcing between leads. A short circuit in the printed circuit board of the motherboard itself or on an expansion board. An improperly installed component. Unfortunately, a component that is smoking has probably already been damaged to some degree. It's unlikely that it will ever function properly again. Replacement components are usually required.

Approval Process

If the change board approves your change request, then the change is proposed to the end user, usually a customer, for approval. Ensure that you receive written approval from all necessary parties to protect yourself and others from misunderstandings and their expensive and destructive effects. Once all parties approve a change, all of the documents associated with a project must be updated to reflect the change, including the project plan, budget, allocated resource documentation, and any other projects the change affects.

Motherboard Installation Facts

If you are replacing an existing motherboard, document the current CMOS settings. You might need these settings to configure the new motherboard. Install the CPU, heat sink, and memory before installing the motherboard in the case. Insert the I/O shield into the case. Fasten standoffs to the case, being sure to match the hole pattern on the motherboard. The standoffs prevent the motherboard circuits from touching the system case. Install the motherboard, securing it to the standoffs with insulated washers and screws. Connect the power and accessory cables:Connect the ATX power cable and the CPU power cable.Connect the CPU fan power cable.Connect case wires (e.g., power switch, reset switch, and drive activity and power lights).Connect any case fan cables. Connect drives to SATA connectors. Install additional devices in expansion slots. Connect wires for front/top panel ports (e.g., USB, audio, or eSATA). Document the settings of the new motherboard.

Not Enough Memory Errors

If you receive Not Enough Memory or Out of Memory errors when you try to open and use more than one program at a time, you may need more physical memory.

Additional Ports

In addition to audio input and output ports, some sound cards also include the following ports: MIDI port to interface with MIDI sound devices FireWire Some high-end audio cards include HDMI video processors and video output, combining the features of an audio card with a video card. The sound card might have 1 or 2 HDMI ports (for input and/or output).

Insert CPU

Inserting the CPU is simple. Handle the CPU by the edges without touching the underneath connectors. Drop the processor into place, then push down on the lever to lock the processor into place when using a Zero Insertion Force (ZIF) socket that uses a lever to allow installation of the processor. Be sure to orient the CPU appropriately with the socket.In most cases, the pin array is keyed so that the CPU can be inserted in only one way.For processors that can be inserted multiple ways, be sure to line up pin 1 on the processor with pin 1 in the processor slot. Pin 1 is typically identified with a dot or a triangle. Fill unused processor slots with a special terminating resistor when installing a processor in a multi-processor system. Be sure that the speed of the processors are the same when adding multiple processors in a multi-processor system, .

Interference

Interference is a signal that corrupts or destroys regular signals. Interference affects signals used by two devices to communicate on a network. Listed below are two types of interference that affect computer networks: Electromagnetic Interference (EMI): EMI is interference that affects wired networking signals. EMI is caused by motors, heavy machinery, and fluorescent lights. Use shielded twisted pair cable to protect signals sent on Ethernet twisted pair cabling. If necessary, use fiber optic cables to eliminate the effects of interference. Radio Frequency Interference (RFI): RFI is interference on the radio channel used by wireless networking devices. RFI can be caused by nearby wireless devices using the same channel, cordless phones, or microwave ovens. Wireless networks that use the 2.4 GHz frequency range (801.11b and 802.11g) are susceptible to RFI. You can reduce RFI by using a wireless networking standard that operates in the 5.75 GHz range or using a different channel for wireless devices.

Intermittent Device Failure

Intermittent device failure occurs when a component occasionally stops working. This usually indicates that the device itself is failing. The best remedy is to replace the failing device because it will fail completely at some point. Immediate replacement prevents this from happening. Intermittent device failures may also be caused by device drivers that aren't functioning properly. Device drivers are software and may contain coding errors. Before replacing a device experiencing intermittent failures, first verify that the latest drivers for that device have been loaded. Sometimes downloading the latest driver and installing it will solve the problem. If it doesn't, then the device itself may need to be replaced.

Overheating

Internal system components within a computer generate a great deal of heat that must be dissipated. Overheating causes premature component failure. Overheating could be caused by several conditions: Inadequate air flow. This may be the result of an inadequate number of fans in the system or fans that are too small. In this situation, additional fans can be added to the system to increase air flow. Improperly installed fans. Fans must be oriented to force air through the system in the same direction, otherwise they may fight against each other and prevent air from flowing properly. Failing fans. A failing fan moves less air than a properly functioning fan. It's not uncommon for a failing fan to generate a screeching noise that is caused by worn parts within the fan assembly. This condition can be fixed by replacing the failing fan. Dust buildup. Excessive dust within the system can block air flow and cause overheating. Use compressed air or an anti-static vacuum to remove dust buildup. Environmental heat. If the air temperature outside the computer is already overly warm, then the temperature inside will be overly warm as well. A properly balanced HVAC system must be implemented in the work area to remove excess heat from the environment. The internal temperature of computer systems should be monitored. Most motherboards include several sensors that can be used to monitor the system temperature. Usually, the current temperature can be viewed within the BIOS/UEFI setup. There are also software applications available that can read the current temperature values from the sensors and display them on screen. Unlike using a BIOS/UEFI monitoring utility, these tools allow the temperature to be monitored dynamically while the system is in use. Most motherboards include a thermal shutdown feature. If the system temperature rises too high, the thermal shutdown feature immediately shuts the computer down to prevent component damage. However, it typically does not shut the system down cleanly, so there is a risk of data corruption if this happens.

Firmware

Is stored on integrated flash memory, on a motherboard.

Hazardous Waste Disposal

It is important to ensure that equipment and hazardous chemicals are disposed of properly. Consult the manufacturer's documentation for recommended solutions for equipment disposal. Consult an MSDS for information on physical data, toxicity, health effects, first aid, storage, disposal, and spill procedures for disposal of hazardous chemicals. You can download an MSDS from the manufacturer's website or check with a representative of that company.

Troubleshooting Tips

Keep in mind the following tips when troubleshooting systems: Often the hardest part of troubleshooting is to reproduce the problem. You might need to ask the user questions to identify exactly how the problem occurred, or you might need to watch them perform the task again to reproduce the problem. If a hardware device or a software program causes a specific error, check the manufacturer's website for additional help in troubleshooting the error. To help diagnose issues, you can run special software tools supplied by the hardware manufacturer. In addition to a basic toolkit, you can keep a few spare parts on hand that you know to be in working order. If you suspect that a component has failed, replace it with the known good spare. If that solves the problem, replace the faulty component. Intermittent problems are particularly difficult to troubleshoot. Check for environmental conditions such as kinked cables or overheated components. If you have problems identifying a hardware error, you can simplify the system by removing all but necessary components (processor, memory, and hard disk). Add devices one at a time and restart the system. If an error occurs, remove the newly added device and troubleshoot that device. Another strategy would be to remove a single device and restart the system, seeing if removing that device corrects the problem. Some problems might be caused by software errors, not hardware failures. You might need to begin by updating the drivers or unloading software. Before you make changes, always consider corporate policies and procedures and the changes' impact on other people and components.

Implement the following measures to defend components from ESD:

Keep the relative humidity in the room at an ideal range of 35-70%, and temperature between 72-77 degrees. The key is to avoid dry air in the computer repair location to prevent ESD. Use antistatic mats under the PC and on the floor. Discharge yourself before touching any computer component. When touching anything inside the computer, wear an antistatic wrist strap that is attached to the metal PC chassis with an alligator clip . Ground both yourself and the computer to the same ground. This provides a single path for the flow of electrical potential. Use static-resistant materials to handle computer components. Never touch the metal connectors on a circuit board. Keep the computer repair location free of materials that accumulate electric charges, such as plastic and Styrofoam. Store sensitive components in static shielding bags, which are usually grey. Static-resistant bags are not nearly as effective. They are usually tinted pink or blue. If a wrist strap is unavailable, keep your body in constant contact with the metal frame when working inside the computer.

Keychain

Keychain is Mac OS's password management utility. Keychain can hold password-protected data for the following categories: Passwords (including passwords for websites, system logins, wireless networks, encrypted disks) Private keys Certificates Secure notes In order to access information contained in Keychain, the system administrator password must be provided.

Known Good Spares

Known good spares are a set of components that you know are in proper functioning order. If you suspect a problem in a component, swap it with the known good component. If the problem is not resolved, troubleshoot other components. Examples of using this strategy are: Changing the cable connecting a computer to the network Connecting a different monitor to a computer Replacing an expansion card

Linux Facts

Linux is an open source operating system. You can even create your own custom version of Linux called a distribution. Some of the more popular Linux distributions include openSUSE, Fedora, and Ubuntu. Like Windows, Linux provides two different user interfaces. There is a a graphical interface where you can click on things with a mouse and make selections to bring up applications. There is also a command line interface called the shell that allows you to enter commands at the shell prompt to manage the system. The command line interface is consistent across all distributions of Linux. Each Linux distribution uses a slightly different graphical user interface. If you learn how to manage Linux systems from within a shell, then you can manage just about any Linux distribution. The shell is often referred to as the bash (Bourne-again shell) shell. A superuser in Linux is equivalent to an administrator in Windows. Linux has two especially important features, command history and command completion. Command history saves commands entered at the shell prompt. The command completion feature tries to guess a command you are entering and will complete the command for you if you press the TAB key. Use the shell commands listed in the following table to manage the file system on Linux.

Liquid cooling

Liquid cooling systems are used when air cooling is not sufficient. Liquid-based cooling systems are composed of tubes, cooling plates, a reservoir, and a radiator. Cooling plates have tubes connected to them and are attached to components. Liquid coolant is then circulated through the system, cooling it. Because liquid cooling can dissipate heat much faster than air cooling, it is primarily used for high-end gaming computers and high-performance systems.

macOS Facts

Mac OS is a proprietary closed-source operating system. Mac OS uses the HFS Plus (HFS+) file system. HFS stands for Hierarchical File System and is the primary file system used by Mac OS. Apple devices have several features that are unique to the Mac OS. The following table describes some of these features.

Magnetic Fields

Magnetic fields located close to a computer can cause undesired effects or even data loss. Hard drives use magnetic charges to store data. While hard disks are shielded and protected from all but the strongest magnets, getting a magnet too close to these components could erase data. Speakers, motors, and generators contain magnets (keep sensitive components away from these devices). Solid state storage devices (such as RAM or flash drives) are not affected by magnetic fields.

Physical

Make sure the room and the building are properly set up to ensure your safety. Keep work areas and floors clear of clutter to help prevent accidents. Do not route cables across the floor in pathways. This can lead to tripping accidents, and could also result in worn cables. Provide adequate ventilation in any enclosure to remove toxic fumes. Protect yourself from airborne particles by using an air filter mask. Wear safety goggles. Replace worn or frayed power cords.

Onboard Components

Many motherboards include onboard components (such as network cards, audio cards, video cards, or USB and FireWire connections). Selecting a motherboard with onboard devices is typically cheaper than buying separate expansion cards for each feature. However, the quality of these onboard devices might not be as high as dedicated expansion cards.

Most modern power supplies eliminate the voltage switch and instead automatically switch between voltages as necessary. These power supplies automatically adjust to accept input voltages in the range of 100 to 240 volts.

Many power supplies have a switch on the back that turns the power on or off. Power supplies are rated in watts. A power supply's watt rating determines its maximum power output. To determine a computer's power requirements, use the following method:Find the watt requirement for each component by multiplying volts by amps (W = V × A).Add each value together to find the total watt requirements.Alternatively, there are several online tools you can use to estimate a computer's watt requirements. ATX power supplies provide soft power, even when the computer is turned off, the motherboard has power. Soft power allows the computer to be turned on and off by the operating system or over the network. When selecting a power supply, make sure it has all the necessary connectors for your components. The following table shows the common power supply connectors:

Error Messages

Memory error usually indicate a failing module or discrepancies between new and old memory. Avoid the latter problem by not mixing new and old memory. Ensure that the memory is functioning properly and is compatible with the system. If the memory is good and fully compatible, these error messages could mean that the motherboard has a problem. The following are some common error messages you may encounter: Memory mismatch error Memory parity interrupt at x Memory address error at x Memory failure at x, read y, expecting z Memory verify error at x

Memory Speed Facts

Memory is rated based on its guaranteed stable operating frequency and bandwidth (the rate at which data can be read or written). Memory ratings help you to differentiate between slower and faster RAM. The following rating systems are used: For all DDR memory (DDR, DDR2, and DDR3), a new designation was introduced to identify that twice the data was being transferred with each bus clock cycle.The number following the DDR-, DDR2-, and DDR3- prefixes is the data transfer rate (twice the bus frequency).For example, DDR-400 matches a bus frequency of 200 MHz; DDR2-800 has a bus frequency of 400 MHz; and DDR3-1600 has a bus frequency of 800 MHz. For DDR past 150 MHz (and for all DDR2 and DDR3 memory), the PC- designation was changed to identify the bandwidth instead of a number derived from the bus frequency.The bandwidth is 16 times the bus frequency, or 8 times the DDR- designation.For example, DDR-400 has a bandwidth of 3200 MB (PC-3200); DDR2-800 has a bandwidth of 6400 MB (PC-6400); and DDR3-1600 has a bandwidth of 12800 MB (PC-12800).For a brief time, the double-frequency designation used the PC- prefix for early DDR modules. For example, PC-200 used with DDR indicates a bus frequency of 100 MHz, not a bandwidth of 100 MB (PC-200 is equivalent to DDR-200 which is equivalent to PC-1600). When listing the frequency, the frequency value usually indicates the bus speed, not the internal frequency (DDR designation) used by the memory. The following table lists the various memory speed designations for the most common memory types:

Mini TRS

Mini TRS ports on the sound card accept 3.5mm plugs for analog audio I/O. The number of ports on the sound card depends on the type of I/O support (e.g., the number of speaker channels, microphone, or line-in support). Ports are often labeled with text or graphics to identify its function. Standardized color coding might also be helpful in determining the proper connection. Pink = Mic in (mic-level) Light blue = Line in (line-level) Lime green = Line out (front speakers or headphones) Black = Line out (rear speakers) Orange = Line out (center and subwoofer)

Mini-ITX Tower

Mini-ITX towers are designed to house mini-ITX motherboards. They are typically smaller than microATX towers.

Mission Control

Mission Control is a desktop and windows management utility used to access several Mac OS features. Multiple Desktops - At the top of Mission Control is the Multiple Desktops feature that is used to manage and navigate between multiple desktops. All Windows - When activated, Mission Control tiles all application windows on the screen and groups multiple windows from the same application together. Dashboard - From Mission Control, the Dashboard containing Mac OS widgets can be accessed.

Mobile Processors

Mobile CPUs are used in mobile computers and cell phones where portability and mobility are a concern. Special versions of processors are built to minimize power consumption and the amount of heat generated.

8-pin EPS12V CPU power

Modern processors consume even more power. The 8-pin EPS12V connector provides four lines of 12 V power. The 8-pin EPS12V was originally used with some older dual processor systems. All modern multi-core processors use this connector. Some power supplies have two 4-pin connectors (4+4) that are meant to be used side-by-side in the 8-pin plug.

Digital Audio

Most audio devices, such as stereo consoles, TVs, and speakers require analog audio. Newer devices, such as some CD players, DVD players, and HDTVs, are capable of processing digital audio signals. Digital audio support in a sound card: Allows you to play digital audio directly from an internal CD player Allows for compression of audio data to support Dolby Digital or DTS surround sound Can use fiber optic cables to eliminate electrical interference Sound cards support digital audio in the following ways: An internal connector on the sound card connects to a digital audio output connector on a CD/DVD drive. Through this connection, you can play CDs directly through the sound card. An internal connector on the sound card sends HD audio, such as from a DVD or Blu-ray disc, to an audio pass-through on a video card. This allows the HD audio signal to be combined with the video signal through an HDMI connector. Sony/Philips Digital Interface Format (S/PDIF) is a consumer standard for digital audio. These are either optical or coaxial external connectors and allow input and output between other digital audio-capable devices.

Configure CMOS Settings

Most motherboards automatically detect the processor speed. If not, you might need to use jumpers or edit the CMOS to configure the processor speed. For newer processors released after the motherboard, you might be able to add support for the processor by updating the BIOS Typically, the processor will run at a speed lower than its rating if the motherboard does not support the higher speed. As a best practice, you should update the BIOS shortly after installing the processor (you must have a processor and memory installed to update the BIOS). An important feature in the BIOS/UEFI is the Execute Disable Bit. Execute Disable Bit (EDB) is an Intel hardware-based security feature that can help reduce system exposure to viruses and malicious code. EDB allows the processor to classify areas in memory where application code can or cannot execute. When a malicious worm attempts to insert code in the buffer, the processor disables code execution, preventing damage and worm propagation. To use Execute Disable Bit, you must have a PC or server with a processor with Execute Disable Bit capability and a supporting operating system. EDB-enabled processors by Intel are indicated by a "J" after the CPU model number. Execute Disable Bit is abbreviated as EDB (by Intel) or XDB.

Memory Slots

Most motherboards have multiple memory slots. Memory slots are designed to be compatible with a specific type of memory module.

Heat sensors

Most motherboards include the following heat sensors: CPU sensor (located on the circuit board underneath the processor) System case sensor (located either on the motherboard or on a cable attached to the motherboard) Room temperature sensor (usually connected to the motherboard by a cable and mounted on a case slot) Special software can monitor the temperature levels and be configured to send warnings when high temperature conditions exist. The BIOS in most motherboards can also be configured to automatically shut the system down when a specified thermal threshold is exceeded.

Motherboards

Motherboards adhere to design specifications called form factors. The form factor determines the physical characteristics of a motherboard, including its dimensions, number of expansion slots, and mounting hole locations, as well as the back panel dimensions, arrangement, and orientation. The following graphic and table describe the characteristics of the most common motherboard form factors:

mv

Moves and/or renames files and directories from one location or name to another. For example, to move the widget.odt file in your current working directory to the /home/rtracy directory, you would enter mv widget.odt /home/rtracy at the shell prompt. Before moving it, you could rename it to newwidget.odt by entering mv widget.odt newwidget.odt or, alternatively, you could rename and move it simultaneously by entering mv widget.odt /home/rtracy/newwidget.odt.

6+2-pin PCIe

Newer video cards require more power than can be supplied through the PCI Express bus. The 6+2-pin PCIe connector plugs directly into the video card to supply additional, dedicated power. The 6+2-pin PCIe: Provides up to 150 watts Is also known as a PEG6+2 (PCI Express Graphics 6+2 pin) Some motherboards have only a 6-pin PCIe connector. These connectors provide up to 75 watts.

Notebook

Notebook cases are generally proprietary and often vary among models.

Distended Capacitors

Over time, the capacitors on the motherboard may become overstressed or overheated. When this happens, they may bulge or even begin to leak fluid. Distended capacitors usually fail at some point, causing the motherboard to fail. For example, if the fans in the power supply spin up when you power on a system, but the motherboard itself doesn't start, it is possible that capacitors on the motherboard have become distended. If this happens, inspect the motherboard and look for capacitors that are swollen on top or leaking brown liquid. While it is possible to carefully replace a failed capacitor on the motherboard, it is usually faster and more cost-effective to replace the entire motherboard.

Overclocking

Overclocking is pushing a CPU beyond its designed specifications. Overclocking can give you a marginal increase in performance, but will decrease your CPU's life. Some Intel processors include a Turbo Boost feature. Turbo Boost, the opposite of throttling, allows the processor to dynamically run above its rated speed to improve performance. Unlocked processors are processors whose speed can be changed above their rated speed through overclocking. With overclocking, you increase the speed and often the voltage to increase the performance of the processor. Overclocking typically voids the CPU warranty and could lead to shorter component lifetimes. Some multi-core processors (such as a triple-core CPU) have additional cores that have been disabled. With the appropriate motherboard support, you might be able to unlock and use the additional core(s). However, stability of the extra cores is not guaranteed.

Peripheral Component Interconnect (PCI)

PCI was developed to replace the obsolete ISA and VESA bus standards. PCI: Is processor independent, meaning the CPU and PCI bus can process concurrently Supports plug-and-play, meaning installed devices are detected and configured automatically Is used most commonly by devices such as sound cards, modems, network cards, and storage device controllers Can run at 33 MHz and transfer data at 133 MBps or run at 66 MHz and transfer data at 266 MBps

PCI Express (PCIe)

PCIe was developed to replace PCI, PCI-X, and AGP. Instead of a shared bus, each PCIe slot links to a switch that prioritizes and routes data through a point-to-point dedicated connection and provides a serial, full-duplex method of transmission. PCIe uses several different connection types. PCIe types are defined by the number of transmission lanes that are used to transfer data. For example, PCIe x1 provides one lane for transmission (x1), while PCIe x16 provides sixteen lanes for transmission. PCIe defines x2, x4, x8, x16, and x32 connection types. PCIe data rates depend on the protocol version and number of transmission lanes:1.0: 250 MBps (x1); 4 GBps (x16)2.0: 500 MBps (x1); 8 GBps (x16)3.0: 1 GBps (x1); 16 GBps (x16)4.0: 2 GBps (x1); 32 GBps (x16) In addition to greatly increased speed, PCIe offers higher quality service. PCIe can run alongside legacy PCI technology (e.g., both PCIe and PCI buses can be in the same system). PCIe x1 slots are typically used for network cards, USB cards, and sound cards. PCIe x16 slots are primarily used for dedicated video cards. PCIe cards are cross-size compatible, as long as the slot size is the same or larger than the card size. For example, a PCIe x1 card can be installed in a PCIe x16 slot, but a PCIe x16 card cannot be installed in a PCIe x1 slot.

Parity RAM

Parity memory is a type of memory that checks for common kinds of internal data corruption. It does not correct internal data corruption. Non-parity memory does not perform error checking. Parity RAM is no longer used. Today, PC systems use ECC for error detection and correction.

Peripherals

Peripherals can present a safety hazard to you. Do not use a regular multimeter or other electrical testing equipment to measure charge inside a monitor. Never clean the monitor's glass with a liquid solvent while the monitor is powered on. Some studies suggest that laser printers emit tiny particles which could be dangerous when inhaled. As a precaution, do not locate laser printers immediately next to desks, and keep the area ventilated. Avoid handling leaky batteries. The leaking electrolytes can be harmful if they get into your eyes. Never look into the end of a fiber optic networking cable. Laser light can damage your eyes.

Power

Power hazards can cause electrical shock and burns. Before handling a system component, make sure that it is powered off and that the main power cord is unplugged from the wall socket. Ensure that the grounding pin on a PC power plug is intact. Unplug the system before working on internal components. Newer power supplies constantly pull power from the socket. Be aware that the power inverter (power supply) converts AC current to DC current. Also be aware that the power supply can retain an electrical charge, even when not plugged in. Replace faulty power supplies instead of trying to repair them. Avoid opening the power supply which houses a capacitor (stores a large charge of electricity).

You should be aware of the following facts about power supplies:

Power supplies should be matched to the motherboard and case form factor (i.e., match an ATX power supply with an ATX motherboard or a microATX power supply with a microATX motherboard). Some power supplies have a voltage switch that toggles between two voltage settings. Depending on the country, typically, the voltage switch can be toggled either between 115 and 230 volts, or between 110 and 220 volts.115 volts is used in North America.230 volts is used in Europe.100 volts is used in Japan.220 volts is used in most parts of Asia.

Power Issues

Power supplies wear out over time, especially if they're overheated or overstressed. If the power supply can't provide adequate amounts of electricity to the system, the computer may exhibit one of several behaviors: It may unexpectedly shut down. It may continuously reboot itself. It may not power on at all. Pin 8 on the power supply connector connects to the power good wire on the motherboard. If power disappears off that wire, the motherboard shuts down. If power quickly reappears on that wire, the system may attempt to come back on by itself, resulting in continual reboots. If power does not reappear on this wire, then the system will shut off. For example, a failing power supply may not provide enough voltage on this wire for the system to initially boot up. If these symptoms are observed, test the power supply to determine if it's the source of the problem. Turn the power supply on and then test the voltage supplied on either a motherboard connector or on a hard disk connector. If the voltage is less than expected, then the power supply may be at fault. For example, if a 12 volt wire is carrying less than 11 volts, the power supply is probably failing. If this is the case, do the following to rectify the issue: Purchase a new power supply. Remove the old power supply from the system Mount the new power supply. Connect the new power supply to the motherboard and to all other internal devices. Power the system on and verify that the symptoms have been eliminated.

Prepare for Installation

Preparing for a CPU installation will help to ensure that your new components are not damaged before installation. Use anti-static protection when installing a CPU. Ensure that the CPU and motherboard socket type match. The socket identifies the number and layout of pins. Verify that the motherboard supports the processor speed. Verify how heat connectivity will be established between the CPU and heatsink.

Backout Plan (Change Order Form)

Present a plan for returning affected systems to their original state if your proposed change to a hardware or software implementation fails.

Speed

Processors operate using an internal clock that is the same as, or is a multiple of, the motherboard bus speed. The speed is represented in megahertz (MHz) and is also referred to as the frequency. You can purchase processors of the same type but with different speed ratings. When selecting a processor, make sure the motherboard supports the processor speed by reading the motherboard documentation first. Most motherboards automatically detect the processor speed. If not, you might need to use jumpers or edit the CMOS to configure the processor speed.

Cooling

Processors require some form of heat dissipation system to function properly. Without a heat dissipation system, a processor will overheat and burn out in less than a minute. CPUs use a heat sink, fan, thermal paste, liquid, or fanless cooling system to transfer heat from the CPU to the cooling unit.

Plan

Provide a plan for implementing the change. This plan may include extending the project schedule, requesting additional resources, requesting additional funding, and any other impacts to the project.

Purpose

Provide an explanation about why you wish to make this change to the project.

RJ11 Connector

RJ11 ports are used by telephones and modems to send analog signals. RJ11 ports have four connector pins.

RJ45

RJ45 ports are used to create Ethernet networks by connecting multiple computers and networking devices. RJ45 ports have eight connector pins.

Nickel Metal Hydride (NiMH) Batteries

Recycle these; NiMH batteries are considered a non-hazardous waste in most U.S. States, with the exception of California.

Lithium and Lithium Ion Batteries

Recycle these; lithium batteries are considered a non-hazardous waste.

PC System

Recycle, give it away, or resell it; a typical PC contains $5 to $25 worth of precious metals. Remember to clean the hard drive before disposing of the machine.

Alkaline Batteries

Recycle, if possible, otherwise dispose of alkaline batteries as your local laws require. For example, in some states, you can throw them in the regular trash. In California, it is illegal to throw them in the common trash. They are considered hazardous waste and are supposed to go with the household hazardous waste collection for special recycling.

Inkjet Printer Cartridges

Recycle; you can return the cartridges to the manufacturer for recycling or recycle them yourself.

Static RAM (SRAM)

SRAM stores data using four transistors for every bit of data. SRAM does not require constant power to maintain the contents of memory. SRAM is more complex and less dense (e.g., lower storage capacity) than DRAM. SRAM is faster and requires less power than DRAM. Regular SRAM still requires periodic power to maintain the state of memory, but the rate of refresh is less than with DRAM. Non-volatile SRAM (nvSRAM) is able to maintain memory contents when the power is turned off. SRAM is typically used in cache memory, such as CPU cache, hard disk cache, and cache in networking devices.

Search

Search is a feature to help you find documents on your computer. Windows includes a new indexing service that catalogs objects and files on your computer to improve the speed of searches on your computer. The search is typically fast because it does not search the complete hard drive but, instead, searches the index. Instant Search provides a box for typing keywords and phrases. As you type, matching results are displayed. Instant Search boxes are available on the taskbar and in other applications such as Internet Explorer, Photo Gallery, and Media Player. Custom properties are tags or descriptions that you can add to files as attributes that can be easily searched or indexed. Search Folders lets you save a search as a folder. When you open the folder again, the search is performed, and the results are displayed.

shutdown

Shuts down or reboots the system in a secure manner. The syntax of the shutdown command is shutdown -h|-r +m message. The options for the shutdown command include: +m specifies when to perform the shutdown operation. m is the amount of time is specified in minutes. -h instructs the system to shut down and power down. -r instructs the system to reboot after the shutdown. -p powers off the machine. message specifies a message that is sent to all users that accompanies the standard shutdown notification.

Radio frequency interference (RFI)

Signals caused by cordless phones, microwave ovens, and wireless devices that interfere with wireless networking.

Single- or Double-Sided

Single-sided RAM has memory modules that are organized into a single logical bank; double-sided RAM has modules organized into two banks. The computer can access data in only one bank at a time. Therefore, single-sided RAM allows access to all of the memory, while with double-sided RAM, the computer must switch between banks. Originally, double-sided RAM had modules on both sides of the circuit board, and single-sided RAM had modules on only one side. However, you can also have double-sided RAM with modules on only one side, where the memory is divided into separate banks internally. Single-sided memory of the same capacity as double-sided memory uses half the number of memory modules (modules are denser, with a higher individual capacity). Some older motherboards are unable to use double-sided memory, while some that allow double-sided memory can use only up to half the total memory when all memory slots are filled, or mixing single- and double-sided together might not be allowed. Most motherboards support both single- and double-sided memory. However, verify compatibility before purchasing.

Software-generated memory problems

Software errors include: Registry error - Parts of the registry are written to faulty sections of RAM. Exception error - A software bug can cause this type of error. General-protection fault - A software bug can cause this type of error. Page fault - A software bug can cause this type of error. For software errors, check to see if the memory address indicated in the error is consistently the same. If so, check the memory. Otherwise, reboot the system or update the software.

High Disk Usage

Some operating systems send data to the hard disk drive if there is not enough physical memory available. If you hear the hard drive constantly operating as you work, or if the hard drive light on the front of the system case stays illuminated for long periods of time, you may need to add more physical memory to the computer.

IEEE 1394

Some sound cards include one or more IEEE 1394 (FireWire) ports. These ports function as normal IEEE 1394 ports.

ESD Facts

Static electricity is the accumulation of a friction-caused electric charge on a non-grounded object. The static charge on the surface of a non-grounded object can jump when it contacts the surface of any grounded object. This electric discharge is known as electrostatic discharge (ESD). ESD can be very destructive to a computer. The threat of ESD begins when the fragile components (including the processor, hard drives, memory, motherboard, and expansion cards) inside the computer are exposed. You can cause damage simply by placing a fingertip too close to a component inside an open computer case. ESD charges can travel through wires and into components, where the wires can explode or fuse together, causing the components to fail. ESD can cause immediate failure of components or could gradually degrade components, causing only intermittent problems. It takes very little ESD to damage a component. A discharge of as little as 10 volts can damage a component, but 3,000 volts or more of ESD must occur before you can even feel it.

Processor Troubleshooting Facts

Symptoms of a failed or failing CPU include: System will not boot. System boots, but the operating system fails to load. System has POST parity problems with a number of devices. System locks up shortly after startup:This symptom is possibly thermal issue. Check for this problem by shutting down, letting the system cool off, and restarting the computer to verify whether the problem repeats itself. Check the following if overheating seems to be the problem:Check the heat sink and fan for placement and condition.Verify that thermal paste or a thermal pad has been used between the processor and the heat sink.Ensure the heat sink is firmly attached to the CPU.Verify that the CPU is properly seated in its socket.Make sure system case fans are working and that the case and expansion slots are in place.If the computer is not overheating but has this symptom, the problem could be the clock or system timers in the BIOS/UEFI are set incorrectly. System sounds a POST beep code indicating a CPU fault upon boot:Verify that the CPU is receiving sufficient power by checking the power outputs.If these are good, replace the CPU.If the fault remains, the problem is with the motherboard. System crashes on startup or when running a software application or certain group of applications:Run repetitive tests using diagnostic software.After replacing a seemingly faulty CPU and the symptom remains, run similar tests on the motherboard and chipset.Do not forget to check for a corrupt file in the software. If the computer boots, but the processor is running at less than its rated speed, check for incorrectly set motherboard settings or use the BIOS/UEFI to set the appropriate CPU speed. If you cannot set the correct speed, try updating the BIOS with the latest version.

When troubleshooting a power supply, keep the following in mind:

Symptoms of bad power supply include:The computer does not turn onThe computer sporadically shuts off or rebootsA broken or noisy fan Before opening up the computer, rule out the obvious. Make sure:The power cord is plugged into the wall.The power switch is in the on position.The voltage switch is set to the correct voltage. Test the power supply using a multimeter or power supply tester. Voltage levels should be within +/- 5% of normal. If they aren't, the power supply is bad or failing and should be replaced.12 V rail should be between 11.4 and 12.6 volts.5 V rail should be between 4.7 and 5.25 volts.3.3 V rail should be between 3.1 and 3.4 volts. Because power supplies carry dangerous levels of electrical current, always take proper safety precautions.Never ground yourself when working on a power supply.Never open or disassemble a power supply. Always replace the entire unit. Some computer manufacturers, such as Dell or HP, produce proprietary power supplies. These power supplies might have a unique shape or use different wiring schematics on connectors. When replacing a power supply, identify whether a standard ATX or a proprietary power supply is required.

System Preferences

System Preferences is the utility used to change settings for nearly every aspect of Mac OS. Settings are grouped by category and can be accessed by selecting the category icon. Each category has multiple tabs or dialogs that are used to change different system settings. The search box can be used to search for the location of a specific setting.

Terminal

Terminal is Mac OS's command line interface utility. It is similar to the terminal used in Linux systems. Terminal: Uses many of the same commands as the Linux terminal. Can be used to perform system management tasks, such as deleting files, changing permissions, etc. Is an excellent troubleshooting tool.

4. Test your theory

Test your theory to verify the cause of the problem. If your theory is not correct, examine other possible causes (return to the previous step). At this point, if the problem is caused by simple things like an unplugged system, you can safely take actions to resolve the problem. If the cause is not a simple one, identify the necessary steps to correct the problem. If you cannot identify the cause of the problem, or if the problem is beyond your ability or responsibility to fix, escalate the problem.Escalation means turning the problem over to someone more capable of handling the problem. When escalating the problem, be sure to detail the actions you took and the information you have discovered up to this point.

24-pin (20+4 pin) ATX connector

The 24-pin ATX power plug supplies power to the motherboard. Some 24-pin connectors have one 20-pin plug and a detachable 4-pin plug. This allows for backwards compatibility with 20-pin motherboards. You can plug a 24-pin ATX power plug into a 20-pin motherboard connector, leaving the four pins unconnected. Older motherboards used 20-pin power plugs. With a 24-pin ATX power plug, the four extra pins supply an additional 3.3, 5, and 12 volts of DC power.

4-pin peripheral power

The 4-pin peripheral power connector (colloquially called a 4-pin Molex connector) is used by legacy components (e.g., IDE hard drives and PATA optical drives), case fans, and other accessory devices. The connector provides both 5 V (red wire) and 12 V (yellow wire). Each power supply cable typically has multiple 4-pin connectors on the same cable. When connecting devices, try to balance the devices connected to each cable.

ATX

The ATX (advanced technology extended) form factor is the most commonly used form factor. Because of its popularity, several variants of the ATX form factor exist. Each variant has different specifications for dimensions and number of expansion slots. However, all ATX variants share the following characteristics: Back plate measurements (6.25" × 1.75") Power supply specifications:24-pin ATX power connectorOn/off switch runs from the case to the motherboardSoft-power control (OS can turn the computer off) Expansion slot locations and spacing (0.8" between slots) Mounting hole locations CPU location (top of board near power supply) Below are the most common ATX variants and their unique characteristics

Basic Input/Output System (BIOS)

The BIOS is a legacy program stored in a read-only memory (ROM) chip that the CPU automatically loads and executes when it receives power. Important things to know about the BIOS are: The BIOS program controls the startup process and loads the operating system into memory. The BIOS is firmware. You should frequently check for BIOS updates from the manufacturer. Updating the BIOS (called flashing the BIOS) makes new features available, such as allowing the BIOS to recognize newer hardware devices. Most BIOS chips vary from 265 KB to 1 MB in size. Video cards include a BIOS chip on the device. These devices have their own ROM chip called an option ROM (OpROM).

BTX

The BTX (balanced technology extended) form factor was designed as a replacement for the ATX form factor. However, it did not gain widespread adoption. With BTX: The CPU is positioned in such a way that air flow is increased. There is no heatsink fan. Instead, a thermal module or shroud fits over the CPU to move heat directly out of the system. The back panel orientation and mounting location is reversed. BTX was implemented mainly by computer manufacturers such as Dell

CMOS Battery

The CMOS battery is used to keep an accurate date and time, even when the motherboard has no power. In older motherboards, the CMOS battery was also used to retain BIOS configuration settings, which were stored in volatile memory called the CMOS chip.

CPU Socket

The CPU socket houses the CPU. There are a variety of CPU socket types, each of which have unique shapes, pin arrangements, or mounting configurations. Because of this, it's important to match the motherboard socket type with the processor socket type. Some motherboards support multiple processors and have a socket for each CPU.

Control Key (Apple)

The Control (^) key is primarily used for text document navigation. For example, Control+H deletes the character to the left of the cursor. The Control key can also be used in conjunction with other keys to perform system tasks. For example, Command+Control+Power button forces the Mac OS to restart. When used in a Boot Camp Windows installation, the Control key serves the same function as the Ctrl key.

DB-15

The DB-15 port is used by legacy gamepads, joysticks, and MIDI devices. These ports are typically found on older sound cards.

Dock

The Dock is the main taskbar in Mac OS. The Dock is used to launch apps, switch between running apps, access the Trash, and access specific folders. Dock settings can be accessed in System Preferences or by right-clicking the Dock and selecting Dock Preferences. Apps and folders can be pinned to the Dock for quick access. Running apps on the Dock have an illuminated dot below them.

Extended ATX(EATX)

The EATX form factor is the largest ATX variant. EATX: Measures 12" × 13" Typically uses extra space for additional memory slots

Electrically Erasable Programmable Read-Only Memory (EEPROM)

The EEPROM is a RAM chip that replaced the CMOS chip. Important things about EEPROM are: EEPROM is a type of non-volatile memory used in computers and other electronic devices to store relatively small amounts of data. EEPROM allows individual bytes to be erased and reprogrammed. EEPROM replaced EPROM chips and are used for computer BIOS built after 1994. EEPROM chips allow you to update the BIOS/UEFI in your computer without having to open the computer and remove any chips.

fn (Apple)

The Fn key is typically only found on Apple notebooks and is used to access the F1-F12 keys on the keyboard. It can also be used to access the special icon function on particular keys.

HDMI and DisplayPort

The High-Definition Multimedia Interface (HDMI) port and DisplayPort are used to send high-quality digital video and audio signals. The following devices use the HDMI and DisplayPort: · LCD monitors · HDTVs HDMI has a smaller form factor connector called an HDMI-mini connector. This connector is half the size of a standard HDMI connector and is used to connect smart phones, tablets, and digital cameras to external displays.

alt option key

The Option (⌥) key is used for application shortcuts and navigation shortcuts. For example, Option+Right/Left Arrow navigates between words in a text document. When used in a Boot Camp Windows installation, the Option key serves the same function as the Alt key.

ITX

The ITX form factor was designed for low-power, small form factor (SFF) computers. The most common ITX form factor is the Mini-ITX form factor. The Mini-ITX form factor: Specifies a maximum motherboard size of 6.7" × 6.7" Has only one expansion slot Allows for small (100 watt) power supplies Is typically used with a home theater PC (HTPC) Other ITX form factors include the following: Nano-ITX (4.7" × 4.7") Pico-ITX (3.9" × 2.85") Mobile-ITX (2.9" × 1.7") The Mini-ITX form factor uses the same mounting locations and back panel specifications as the ATX form factor, allowing Mini-ITX motherboards to fit in ATX cases.

The system boots, but the memory count is incorrect

The POST failed to recognize all of the memory. This can happen with incompatible memory installation. Remember to avoid combining dual-bank with single-bank memory. If any problem is detected during system boot, check the BIOS settings. The system will check only for memory installed in memory slots on the motherboard. Memory that is on expansion cards or installed on other devices will not be counted and tested.

PS/2 (Mini-DIN-6)

The PS/2 port, also called mini-DIN-6, is used to connect older PS/2 keyboard or mouse devices. PS/2 ports are color coded: Purple denotes the keyboard port. Green denotes the mouse port. The PS/2 port has been superseded by the USB port.

Coaxial S/PDIF & Fiber S/PDIF

The S/PDIF port is used to send a digital audio signal to high-end audio devices, such as home theatre systems or Dolby Digital surround sound systems. Coaxial S/PDIF ports use a copper coaxial cable to transmit signals. Fiber S/PDIF ports use fiber optic cables to transmit signals.

SATA power

The SATA power connector has 15 pins and provides 3.3, 5, and 12 volts. As its name implies, it powers SATA devices. You can use a special adapter to convert a 4-pin peripheral power connector to a SATA connector. When using an adapter, or on some power supplies, the connector supplies only 5 and 12 volts.

Start

The Start is the easiest way to access the most useful things on your computer. The list of programs in the Start is divided by a separator line into two sections, pinned default programs and the most used programs. The Start can be customized for each user. The Start's appearance is different with each Windows version. The Start is found in Windows 7 and 10.

Thunderbolt

The Thunderbolt port combines PCI Express (PCIe) and DisplayPort signals into a single interface. The Thunderbolt port can also provide DC power. Thunderbolt ports are mainly used for external displays.

Unified Extensible Firmware Interface (UEFI)

The UEFI was designed to replace the BIOS. Important things about UEFI are: The UEFI is firmware. The UEFI program controls the startup process and loads the operating system into memory. The UEFI design improves the software interoperability and the address limitations of BIOS. The UEFI provides better security to protect against bootkit (malware attacks on the boot process) attacks. The UEFI provides faster startup times. The UEFI supports drives larger than 2.2 terabytes. The UEFI supports 64-bit firmware device drivers. The UEFI is compatible with both BIOS and UEFI hardware. You should frequently check for UEFI updates from the manufacturer. Updating the UEFI (called flashing the UEFI) makes new features available.

Capacity

The capacity (sometimes called the size) refers to the storage capacity of the memory module (e.g., 256 MB, 512 MB, 1 GB). The total capacity of memory that you can install in your system is limited by: The number of memory slots on the motherboard. The maximum total capacity that can be installed. For example, most systems will have a maximum capacity of between 3 GB and 16 GB of RAM. The maximum module capacity. For example, the motherboard might only be able to accept up to 2 GB or 4 GB modules. The maximum amount of memory that can be addressed (used) by the operating system. A 32-bit operating system can use between 3 GB and 4 GB of memory, while a 64-bit operating system can use more.You can install more than 4 GB of memory in a system that uses a 32-bit operating system; however, the operating system will be able to use only between 3 GB and 4 GB of that memory. If your motherboard had a total of three slots, with a maximum module size of 1 GB and a system maximum of 3 GB, and if you had two 512 MB modules installed, you would be able to add only a single 1 GB module bringing the total up to 2 GB. You could also replace one or both of the 512 MB modules bringing the total to 2.5 or 3 GB respectively.

Chipset

The chipset is a group of chips that facilitates communication between the processor, memory, and peripheral devices. With chipsets: The memory controller and graphics controller are on the CPU. The remaining functionality is combined into a single controller chip.Intel processors use the Platform Controller Hub (PCH).AMD processors use the Fusion Controller Hub (FCH). The front-side bus is replaced by the Direct Media Interface (DMI).

Kernel

The core of the operating system that is loaded into memory when the system boots up.

Desktop

The desktop is the working surface that contains icons that access programs, files, applications, and file systems. The desktop is what is seen when all programs and open folders are minimized. Installing an application often adds an icon to the desktop.

Scope

The extent of a project, area, or subject; what is included and what is not.

Utilities

The features or programs included with an operating system that perform system-related tasks.

Firmware

The firmware on a motherboard is stored on integrated flash memory. Motherboards use one of two firmware implementations: BIOS (Basic Input/Output System) UEFI (Unified Extensible Firmware Interface) Older motherboards stored the BIOS on removable, read-only memory (ROM) chips.

Processing

The flow of data through a series of procedures as defined by a set of instructions. Major processing components include: CPU (central processing unit) RAM (random-access memory)

Electrostatic Discharge (ESD)

The flow of electricity from one electrically charged object to another.

Install Heat Sink and Fan

The heat sink and fan are installed on top of the CPU. CPUs require a heat sink and most desktop systems also use a fan for cooling. When installing a heat sink, use thermal grease or a thermal pad between the processor die and the heat sink. This maximizes heat transfer between the processor and the CPU.

Kernel (Windows)

The kernel is the core of the operating system that is loaded into memory when the system boots up. It is responsible for controlling security, managing the file system, and providing a platform for applications to run on. The user rarely interacts directly with the kernel.

microATX

The microATX form factor is a smaller version of the ATX form factor. The microATX form factor: Measures 9.6" × 9.6" Has four expansion slots

System Cooling Facts

The normal operation of computer components produces heat. Overheated components can cause intermittent errors and reduce component life. If components are overheated for an extended period of time, they will fail. To keep component temperatures optimal, computer cases maintain a consistent, one-way flow of air through the case. This lesson covers the following topics: Airflow in a computer case Cooling system components Cooling system recommendations Airflow in a Computer Case The following diagram shows how air should flow through a computer case:

Notification Area

The notification area is a part of the taskbar located on the right side of the taskbar. The notification area: Displays the time and date. Displays icons that represent the applications and processes running behind the scenes on your computer, such as audio volume and security programs. Displays connectivity to the internet or a workgroup.

Parallel (DB-25)

The parallel port connects older devices that use a parallel interface, such as printers, hard drives, and gamepads. The parallel port was superseded by the USB and RJ45 port.

Hardware

The physical components that compose a computer system or network. Common hardware components include the following: Keyboard, mouse, monitor, printer Connectors and cables Hard disk drives Circuit boards

Networking and Communications

The practice of connecting two or more computers in order to transfer data. Networking components include: Connecting media: Copper cables Radio signals Connection devices: Routers Switches

Sampling Rate

The sampling rate is the number of analog signal samples taken in over a period of time. Sample rates are expressed in cycles per second, called hertz (1,000 hertz (Hz) = 1 kilohertz (kHz)). A high sampling rate gives a more accurate representation of the sound. Examples of different sampling rates include: 8 kHz (telephone) This is adequate for conversation because the human voice's full range is about 4 kHz. 22 kHz (radio quality). 44 kHz (CD quality) This sample rate can accurately reproduce the audio frequencies up to 20,500 hertz, covering the full range of human hearing. 48 kHz (Digital TV, DVD movies). 96 kHz (DVD audio). 192 kHz, used by:LPCM (Linear Pulse Code Modulation), a DVD-music production format.BD-ROM (Blu-ray Disc-ROM). Higher sample rates require more bits of data per sample. 8-bit sound cards use a sampling size of 256. 16-bit sound cards use a sampling size of 65,536. 20-bit sound cards use a sampling size of 1,048,576. 24-bit sound cards use a sampling size of 16,777,216. 32-bit sound cards use a sampling size of 4,294,967,296. The bit portion of a sound card's sampling size does not correspond with the bus size.

S-Video (miniDin-4)

The separated video (s-video) port is used for connecting external displays. It has slightly better picture quality than an RCA video port.

Serial (DB-9)

The serial port is used to connect serial devices, such as a barcode scanner, dial-up modem, or serial mouse. Serial ports are also used to configure and manage some networking devices. RS-232 is a standard for serial communication transmission of data. It defines the signals connecting computer equipment like a computer and a modem. The RS-232 standard was commonly used in computer serial ports. USB has replaced RS-232 for most of its peripheral interface roles. Many computers no longer come equipped with RS-232 ports.

Standard ATX

The standard ATX form factor is the form factor that all other variants are modeled after. ATX motherboards:Measure 12" × 9.6"Have up to seven expansion slotsHave between six and nine mounting holes

Internal Connectors

There are a number of connectors on motherboards for components such as power supplies, fans, and LED lights. Computer cases often have front panel ports (e.g., USB, FireWire, or audio ports) that need to be connected to the motherboard. These ports are connected to the motherboard's front panel connectors, which are also called headers. External ports that are not available on the motherboard are often added using expansion cards.

Button Batteries

These are considered hazardous waste because they contain mercuric oxide, lithium, silver oxide or zinc-air. Return to manufacturer, recycle, or contact local authorities for disposal procedures.

Nickel-Cadmium (NiCad) Batteries

These are considered hazardous waste; take these batteries to either a household hazardous waste site or a recycling center.

Throttling

Throttling is the process of modifying the operating characteristics of a processor based on current conditions. Throttling is often used in mobile processors to change the operating frequency to minimize power consumption and heat output. Throttling can also be used in low memory conditions to slow down the processing of I/O memory requests, processing one sequence at a time in the order the request was received. Related to throttling, processors or the operating system can shut down unused cores in multi-core systems to conserve energy.

5. Create an action plan

To create an action plan, address the most likely problem and account for side effects of the proposed plan. For example, Will the fix result in significant system downtime? Is the resolution best left for other times of the day? Is there a temporary solution that should be implemented immediately? When side effects have been weighed against the fix and all concerns have been addressed, fix the problem.

Integrated Memory Controller

To improve performance, some processors include the memory controller with an integrated graphics processing unit (GPU) on the processor die, resulting in faster memory access by the processor.

Change Order Form

To request permission to make a change, you must submit a change order form to a change board. A change order form is a document used only to request permission to make changes to a project. A change board is a predetermined group of people who have the power to accept or reject proposed project changes. It may include managers, project managers, or even the CEO.

Troubleshoot Sound Problems

To troubleshoot sound problems, try the following: Make sure that the speakers are connected to the sound card and that the speakers have power. Check the volume setting on the speaker and the back of the sound card (if present). Check software sound settings. Verify that the sound is not muted and check mixer settings. If some files play but others do not, make sure you have the right codecs installed for playing that file type. If you are working with a built-in audio interface, verify that it is correctly configured in the BIOS. If you have installed an add-in card, make sure the built-in audio is disabled. If no sound plays, make sure the card is seated, check for resource conflicts, and update the drivers if necessary. Ensure that the sound card is not experiencing electromagnetic interference (EMI) from the disk drive or power supply. To remedy this problem, move the affected card to an expansion slot located away from the source of EMI.

Troubleshoot

Use the following troubleshooting tips if you are having problems with your installation: Spontaneous reboot or intermittent system crashes: An overheated CPU will cause a spontaneous reboot or intermittent system crashes. A spontaneous reboot can also be caused by a bad power supply or device driver. A clicking noise when reading or writing data from the hard disk is an early sign of a failing drive. System lockups and restarts: Because you have just replaced the processor, the most likely cause of the problem is related to the CPU. System lockups and restarts can be caused by an overheated processor. Make sure the CPU fan is running, and that you have used thermal paste between the CPU and the heat sink. System beeps regularly, nothing is shown on the screen and it doesn't start: Flashing the BIOS is often required to upgrade system components that are part of the motherboard, such as to upgrade to a faster processor. If the motherboard lists the processor as supported but it is not correctly recognized, update the BIOS to the latest version. Before you can do this, you must reinstall the old processor in the system to get it back up and running again. Press F8 while booting to enter the advanced boot menu when Windows loads. However, this option assumes the BIOS has loaded correctly and the computer passed the POST tests. Replacing the motherboard is likely not required as the motherboard was working correctly and the documentation states the CPU is compatible with the motherboard. Replace the CPU only after you have determined that it is faulty.

VGA to DVI

Used to connect a VGA cable to a DVI port.

VGA to HDMI

Used to connect a VGA cable to an HDMI port.

HDMI to DVI

Used to connect an HDMI cable to a DVI port

Ethernet to USB

Used to connect an RJ45 connector to a USB port.

User Account Control (UAC)

User Account Control (UAC) is a feature that helps minimize the dangers of unwanted actions or unintended software installations. UAC differentiates between standard user privileges and administrative privileges. Icons next to some tasks identify tasks that require administrative privileges. In addition, performing other tasks, such as installing applications or hardware devices, require administrative privileges. If standard user privileges are not sufficient to perform a task, the system requests privilege elevation.If you are logged on as a standard user, you are prompted to supply the username and password for an administrator user. If you are logged on as an administrator, you are prompted for permission before the action is performed.

Virtualization

Virtualization is the ability to install and run multiple operating systems simultaneously on a single physical machine. Virtualization typically includes the following components: a physical machine, hypervisor, virtual machine, and virtual hard disk (VHD). The virtual machines appear as self-contained and separate physical systems. Virtualization is performed by adding a thin layer of software, called a hypervisor, between the physical system and the operating system. A hypervisor allows virtual machines to interact with the hardware without going through the host operating system. Early virtualization was performed using software only. Newer virtualization uses special instructions supported by the processor to improve performance. There are several different types of hypervisor software.VMware Workstation and ESX (made by VMware) Hyper-V (made by Microsoft)XEN (open source) If you are planning on implementing a virtual solution, check to see whether hardware support in the CPU is required. Hardware support is provided by processors with the following features:Intel's Virtualization Technology (VT)AMD's AMD Virtualization (AMD-V)

Interface

What allows the user to interact with the kernel and the utilities.

CPU Socket Facts

When choosing a motherboard, you need to ensure that the board is compatible with the system CPU that you intend to use. Your motherboard has a socket that accepts the processor. The processor socket on the motherboard must match the socket type used by the processor. Some motherboards support multiple processors and will have a socket for each one. Processor sockets can be categorized according to how the processor makes contact with the leads in the processor socket. Pin Grid Array (PGA): PGA processors implement a series of pins on the underside of the processor package in an array. The pins are inserted into corresponding receptacles within the processor socket on the motherboard. Land Grid Array (LGA): The LGA socket moves the connecting pins from the processor package to the socket itself. Conducting pads are implemented on the bottom of the processor that contact the protruding pins from the processor socket. Some commonly-implemented processor sockets include the following: Intel:775: Used with the Intel Pentium 4, Celeron D, Intel Pentium 4 Extreme Edition, Pentium D, Pentium Dual-Core, Core 2 Duo, Core 2 Extreme, Core 2 Quad, Xeon, and Celeron processors.1155: Used with the Intel Pentium 4, Celeron, Core i3, Core i5, Core i7, Core i7 Extreme, and Xeon processors.1156: Used with the Intel Pentium 4, Celeron, Core i3, Core i5, Core i7, and Xeon processors.1366: Used with the Intel Celeron, Core i7, and Xeon processors.1150: Used with the Intel Celeron Dual-Core, Pentium Dual-Core, Core i3, Core i5, Core i7, Core i7 Extreme, and Xeon processors.2011: Used with the Intel Core i7 and Xeon processors. AMD:AM3: Used with the AMD Phenom II, Athlon II, Sempron, and Opteron processors.AM3+: Used with the AMD Phenom II, Athlon II, Sempron, and Opteron processors.FM1: Used with the AMD Athlon II processor along with the A-series APUs.FM2: Used with the AMD A4 series, A6 series, A8 series, A10 series, Athlon X2, Athlon X4, FirePro, and Sempron processors.FM2+: Used with the AMD A4 series, A6 series, A8 series, A10 series, Athlon X2, and Athlon X4 processors.

Memory Speed Facts

When comparing the speed of memory modules, be aware of the following: The most useful way to compare most DDR modules will be to compare the amount of data that can be transferred per second (bandwidth), as indicated by the PC- designations. For example, PC-3200 will always indicate a "faster" memory module than one with a PC-2700 rating. PC- numbers up to PC-266 identify the frequency (or double the frequency), not the bandwidth. For example, a PC-266 module has a greater bandwidth than a PC-1600 module (PC-266 = PC-2100). Comparing DDR- numbers can also give you an idea of the relative bandwidth. For example, DDR-600 can transfer more data than a DDR2-400 module. The bandwidth identifies a theoretical maximum that the memory can transfer in a given time period, and is directly related to the front size bus frequency. If you can derive the bus frequency, you can also get a relative idea of the amount of data a module can handle.When comparing DDR modules, the frequency is relative to the bandwidth.For example, a DDR2 module operating on a 533 MHz bus is faster than a DDR3 module on a 400 MHz bus. Other memory characteristics besides the frequency could affect the effective bandwidth or actual speed of the memory module. Another method for increasing memory bandwidth is by providing multiple channels within the memory controller. Dual-channel systems use two memory controllers, while triple-channel systems use three memory controllers. Quadruple-channel (quad-channel) systems use four memory controllers. Each memory controller can communicate with one or more memory modules at the same time. To operate in dual-channel mode, install memory in pairs; to operate in triple-channel mode, install memory in sets of three. To operate in quad-channel mode, install memory in sets of four Dual-channel systems theoretically double the bandwidth. However, in practice, only a 5-15% increase is gained. Dual-channel, triple-channel, and quad-channel support is mainly a function of the motherboard (e.g., the memory controller), not the memory itself. DDR, DDR2, DDR3, and DDR4 can all work in dual-channel systems (depending on the memory supported by the motherboard); both a triple-channel and a quad-channel system use DDR3 and DDR4.

1. Identify the problem

When identifying the problem, resist the urge to start fixing things at this point. To identify the problem: Ask the user to describe the problem, check for error messages, or recreate the problem. Establish what has changed. Most often, problems are caused by new hardware, software, or changes to the configuration. If necessary, carefully ask users to discover what might have changed that could have caused the problem. Remember to inquire about environmental and infrastructure changes that could be relevant. Review system and application logs. Check knowledge base articles, network topology diagrams, and any other documents that may provide helpful information.

Memory Installation Facts

When installing memory remember that modules are very sensitive to ESD. Be sure to take proper steps to prevent ESD. You can add single memory modules to computers that use DDR (including 2, 3, and 4). Install memory in the correct slot. Although several memory slots might be open, some system boards require that you use specific slots. Check the system board documentation for more details.For many systems, start with the first bank. The first memory bank is often closest to the processor.On some systems you should fill each bank in order. Align the memory before inserting, and do not force the module in place. Most memory is keyed to prevent it from being installed backwards or in incompatible slots. Most RAM is held in place with small tabs on either end. To remove RAM from a motherboard, push the tabs down to rotate them back, then pull the RAM straight up. For a dual-, triple-, and quad-channel configuration:Modules must be installed in matching sets (capacity and speed), preferably of the same manufacturer and model.You can typically use different capacity modules between sets. For example, you can use two 1 GB modules as one set and two 512 MB modules in the second set.Install modules in the slots specified in the motherboard documentation. Many motherboards color the slots, with slots used within a set having the same color.If you install single memory modules, the system will continue to use the memory, but cannot use the memory in dual-channel mode. Following installation, power on the system and check for errors. Most BIOS programs include a memory count that displays the total amount of system memory. If it does not count the proper amount of memory, you may have installed the memory incorrectly or you may have a faulty memory module. Also, if the BIOS generates an error between 200 and 299, the error is a memory error. Most systems will configure memory settings (frequency, voltage, and timing including latency) automatically based on information in the EEPROM chip. If necessary, edit the BIOS to manually configure memory settings.

Video Card Installation Facts

When installing video cards, it's important to do it properly so as to not damage your computer or the card itself. Use the following process to install a dedicated video card: Video cards must be compatible with the expansion slots on the motherboard. If the motherboard has integrated graphics, disable it in the CMOS configuration when installing a dedicated video card. Install the video card in the first open expansion slot. If using a multi-GPU configuration (SLI or CrossFire):Install the secondary video card in the next open expansion slot.Link the two video cards together using the bridge clip. Connect any additional power connectors to the video card(s) (e.g., 6-pin or 8-pin auxiliary power).Some motherboards have an additional power connector near the expansion slots that are used with multi-GPU configurations. Connect the external display to the video card using the appropriate cable. When using a multi-GPU configuration, connect the monitor to the primary (first) video card. After installing the video card and making all necessary connections, turn on the computer. In the operating system, install the video card drivers. If using a multi-GPU configuration, install all necessary configuration software.

Connect Fan Power

When the CPU includes a fan, be sure to connect the fan power to the motherboard.

Packaging (Form)

When you are purchasing RAM for a system, the most important consideration is the packaging, also called memory form. The packaging controls both the physical size of the memory module and the memory standard (e.g., DDR2, DDR3, DDR4). If you purchase the wrong type of RAM, it will most likely not fit. If it does, it might have different voltage requirements than what is supported by your motherboard. Memory packaging (memory form) and capacity must match what is supported by the motherboard.

6. Test the solution

When you are testing your solution, do the following: Ensure that the problem is fully resolved and that implementation did not cause any new problems. If necessary, take additional actions to prevent the problem from happening again.

Windows Explorer

Windows Explorer is a graphical user interface (GUI) for viewing and managing the file system.