Chapter 1 Introduction to Computer Repair

A technician must be able to identify these ports readily to ensure that:

(1) the correct cable plugs into each port and (2) the technician can troubleshoot problems in the right area.

RAM and ROM chips come in different styles: DIP (dual inline package), DIMM (dual inline memory module), and RIMM (a memory module developed by Rambus).

Computer and mobile device DIMMs are the most common type of RAM found in computers. Some ROMs are DIP chips. They are usually distinguishable by a sticker that shows the manufacturer, version, and date produced.

Operating System Examples of operating systems:Windows XP, Windows Vista, Windows 7, Windows 8, OS X, arious types of Unix, such as Red Hat and Mandrake.

Which coordinates the interaction between hardware and software applications. The operating system also handles the interaction between a user and the omputer.

The best quality a technician can possess is logic. A good technician narrows a problem to a general area, subdivides the problem into possible culprits, and eliminates the possibilities one-by-one efficiently and logically.

A technician is like a detective, constantly looking for clues, using common sense and deductive reasoning, gathering information from the computer and the computer user, and finally solving the mystery.

Every computer needs an important piece of software called an operating system,

which coordinates the interaction between hardware and software applications. The operating system also handles the interaction between a user and the computer. Examples of operating systems include Windows XP, Windows Vista, Windows 7, Windows 8, OS X, and various types of Unix, such as Red Hat and Mandrake.

Some connectors on integrated motherboards are either D-Shell connectors or DIN connectors

A D-shell connector has more pins or holes on top than on the bottom, so a cable connected to the D-shell connector can be inserted in only one direction and cannot be accidentally flipped upside down. Many documents represent a D-shell connector by using the letters DB, a hyphen, and the number of pins—for example, DB-9, DB-15, or DB-25. A mini-DIN connector is round with small holes and is normally keyed. When a connector is keyed, the cable can only be inserted one way. Keyboard and mouse connectors, commonly called PS/2 ports, are examples of mini-DIN connectors. Today, a keyboard and mouse can also be connected to USB ports (as discussed later in the chapter).

The VGA port was designed for analog output. A mini-VGA port is also available on some mobile devices.

A newer port is a DVI port (Digital Visual Interface), and it has three rows of square holes. DVI ports are used to connect flat panel digital displays.

Once the computer cover or side is opened or removed, the parts inside can be identified. The easiest part to identify is the power supply, which is the metal box normally located in a back corner of the case.

A power cord goes from the power supply to a wall outlet or surge strip. One purpose of the power supply is to convert the AC voltage that comes out of the outlet to DC voltage. The power supply distributes this DC voltage using power cables that connect to the various internal computer parts. A fan located inside the power supply keeps the computer cool, which avoids damage to the components.

An adapter may control multiple devices, such as the microphone and speakers. An alternative to an adapter plugging directly into the motherboard is the use of a riser board Figure 1.8 shows how to install a riser board.

A riser board plugs into the motherboard and has its own expansion slots. Adapters can plug into these expansion slots instead of directly into the motherboard. Riser boards are used with rack-mounted servers and low-profile desktop computer models. The riser card is commonly inserted into a motherboard slot or attached using screws.

Output device

Accepts data from computer. Example Monitor Touch Screen monitor - input and output K

A device may have a cable that connects the device to the motherboard. Other devices require an adapter.

Adapters are electronic circuit cards that normally plug into an expansion slot on the motherboard. Other names for an adapter are controller, card, controller card, circuit card, circuit board, and adapter board.

KVM (Keyboard, Video, Mouse

Can be both input/output. Allows connectivity of multiple devices so they can be shared between computers. For example one Keyboard, one mouse, and one display could connect to a KVM switch.

Bluetooth: Includes 128-bit security and works in the 2.4GHz range. There are three classes of devices, with ranges up to 19.6 feet (6 meters), 72.1 feet (22 meters), and 328 feet (100 meters). Up to eight devices can be connected in a master-slave relationship, with only one device being the master.

Check for interference from other devices, including wireless devices on the same frequency. Also look for Windows, Apple iOS, or Android configuration issues.

Active listening means that you truly listen to what a person (especially one who is having a problem) is saying.

Clarify customer statements by asking pertinent questions and avoid interrupting the customer. Allow customers to complete their sentences. Many technicians jump into a problem the moment they hear the first symptom described by the user. Listen to the entire problem. Do not act superior because you know

Firmware

Combines hardware and software into important chips inside the computer. Chips who has a built in software. Example is BIOS (Basic Input Output System

How to identify an adapter's function Tracing the cable(s) attached to an adapter or looking at a device connected to an adapter can usually help with identifying an adapter's function.

For example, typically a monitor has a cable going between it and a video adapter or motherboard.

Mobile devices, such as smartphones as well as some desktop displays, use touch and multitouch technologies to allow a finger or a stylus to interface with the operating system.

HTC Corporation's TouchFlo technology allows distinguishing between a finger and a stylus and responds appropriately, depending on the input method used. Swiping is used to go to the next page of applica- tions or go to the next photo.

The hard drive, sometimes called hard disk,

Is a rectangular box normally inside the computer's case that is sealed to keep out dust and dirt.

Many input devices, such as keyboards, mice, and headphones, have wireless connectivity. Technologies used to connect without a cord include infrared, radio, and Bluetooth.

Many computing devices, especially smartphones and other mobile devices, have cordless connectivity integrated into the device; otherwise, a transceiver is connected to a USB port to allow connectivity to the computing device.

Keyboards are input devices that connect to the keyboard port. There are two main types of keyboards: mechanical and capacitive.

Mechanical keyboards are the cheapest and most common type. They use a switch that closes when a key is epressed. When the switch gets dirty, it sticks. Mechanical keyboards require more cleaning and are more error-prone than their capacitive counterparts. A capacitive keyboard is more reliable and more expensive than a mechanical keyboard because of the electronics involved in the design.

Memory is an important part of any computing device. .

Memory chips hold applications, part of the operating system, and user documents. Two basic types of memory are RAM and ROM

Tablets and smartphones frequently have no field serviceable parts (parts that can be replaced by a technician) and are typically not upgradable except for memory.

Mobile devices and laptops do have RAM. Sometimes this RAM is not upgradable in mobile devices such as tablets and smartphones. However, storage is sometimes available using flash memory.

An optical drive holds discs (CDs, DVDs, or BDs) that have data, music, video, or software applications on them.

Mobile devices such as tablets and smartphones don't have storage devices such as this.

A port is a connector on a motherboard or on a separate adapter that allows a device to connect to a computer. Sometimes a motherboard has ports built directly into the motherboard.

Motherboards that have ports built into them are called integrated motherboards.

To protect yourself and the computer, make sure to power off the computer and remove the power cord when disassembling, installing, or removing hardware, or doing preventive maintenance (cleaning).

Never take an older CRT monitor or power supply apart unless you have been specifically trained on these components.

There are two basic types of mice—mechanical and optical. A mechanical mouse uses a rubber ball inserted into the bottom of the mouse. The rubber ball turns small metal, rubber, or plastic rollers mounted on the sides. The rollers relay the mouse movement to the computer.

On the other hand, an optical mouse has optical sensors that detect the direction in which the mouse ball moves. It uses reflections from LEDs from almost any surface to detect the mouse location.

ROM (read-only memory) is nonvolatile memory because data stays inside the chip even when the computer is turned off.

ROM chips are sometimes installed on adapters such as a network or video card.

A video port is used to connect a monitor. Video output can be the older method of analog (varying levels, such as seen with an audio signal) or the newer output method of digital (1s and 0s).

Since the computer uses all digital signals, sending 1s and 0s is more efficient than having to convert the 1s and 0s to an analog signal.

Hardware is something you can touch and feel—the physical computer and the parts inside the computer are examples of hardware. The monitor, keyboard, and mouse are hardware components.

Software interacts with the hardware. Windows, Linux, OS X, Microsoft Office, Solitaire, Google Chrome, Adobe Acrobat Reader, and WordPerfect are examples of software.

A device driver

Special piece of software designed to enable a hardware component. The device driver enables the operating system to recognize, control, and use the hardware component. Device drivers are hardware and operating system specific.

A device driver is a special piece of software designed to enable a hardware component.

The device driver enables the operating system to recognize, control, and use the hardware component. Device drivers are hardware and operating system specific. For example, a printer requires a specific device driver when connected to a computer loaded with Windows XP.

The kernel is the central part of an operating system.

The kernel is the connection between hardware and the applications being used.

The motherboard is the main circuit board located inside a PC and contains the most electronics. It is normally located on the bottom of a desktop or laptop computer and mounted on the side of a tower computer.

The motherboard is the largest electronic circuit board in the computer. The keyboard frequently connects directly to the back of the motherboard, although some computers have a keyboard connection in the front of the case.

There are several types of DVI connectors, and the one used depends on the type of monitor attached. Two terms used with these DVI connectors are single link and dual link. A single link connection allows video resolutions up to 1920×1080. With a dual link connection, more pins are available to send more signals, thus allowing higher resolutions.

The two major types of connectors are DVI-D and DVI-I. DVI-D is used for digital video connectivity only. DVI-I can be used for both digital and analog monitors and is the most common. A less common type is DVI-A, which is not shown in Figure 1.24 with the other DVI connector types.

Radio: Works in the 27MHz or 2.4GHz

Troubleshoot: Check for interference from frequency range. Longer distances are other devices, including supported than with infrared. wireless devices on the same frequency.

Infrared Input device Used for very short distances.

Troubleshoot: Check line of sight; check if device or battery is charged; ensure that no bright light, such as sunlight, is interfering with communication.

Input device

Used to put data into the computer. Ex: Keyboard, Microphone, and Mouse

RAM (random access memory) is the most common in all computing devices and is volatile memory—that is, the data inside the chips is lost when power is removed.

When a user types a document in a word processing program, both the word processing application and the document are in RAM. If the user turns the computer off without saving the document to removable media or the hard drive, the document is lost because the information does not stay in RAM when power is removed.

An upgrade to DVI is HDMI (High-Definition Multimedi

Which is a digital interface that can carry audio and video over the same cable. HDMI is found on cable TV boxes, televisions, video adapters, laptops, desktops, and tablets

Laptops and netbooks usually have integrated keyboards as well as a variety of mouse replacement devices, such as trackpoint, touchpad, and/or one or two buttons used for clicking and right-clicking.

You should always remove the battery and AC power cord before removing a laptop keyboard or any other internal laptop part. To remove a laptop keyboard, you commonly remove screws from the top or bottom of the laptop and slide or lift the keyboard out of the case. Always refer to the manufacturer's documentation before removing or replacing a laptop keyboard.

Flash memory is very common with USB-based thumb drives used with PCs and laptops and is nonvolatile—

that is, data is not lost when power is removed. Flash memory cards for mobile devices include CompactFlash and various types of SD (Secure Digital) cards: SD, miniSD, microSD, and xD (extreme digital). Figure 1.12 shows a photo of two of these memory cards.