NET-103 (Chapter 9)

Laptop or Notebook Computer

Is a lightweight, compact, battery-powered computer. The primary goal behind laptops is to have the same functionality as a desktop computer, but in a portable format.

Port Replicator / Docking Station

A port replicator or docking station attaches to a laptop computer and allows you to connect multiple devices such as a mouse, keyboard, printer, network connection, or additional monitors.

Inverter

A power supply that converts DC power from a computer to AC power for a screen.

Light-emitting diode

A semiconductor device that emits light when an electric current passes through it.

Software development kit (SDK)

A set of software development tools that allows the creation of applications for a certain software package, software framework, hardware platform, computer system, video game console, operating system, or similar development platform.

Global Positioning System (GPS)

A space-based navigation system that provides location and time information in all weather conditions anywhere on or near the Earth where there is an unobstructed line of sight to four or more GPS satellites.

Hibernate

A system power state where the system appears to be off and power consumption is reduced to a lower level.

Sleep

A system power state where they system appears to be off, but volatile memory is refreshed and some components remain powered so the computer can wake up quickly if it receives input from a keyboard, LAN, or USB device.

Primary Rate Interface (PRI)

A telecommunications interface standard used on an Integrated Services Digital Network (ISDN) to carry multiple DS0 voice and data transmissions between the network and a user.

International Mobile Subscriber Identity (IMSI)

A unique identifier that defines a subscriber in the wireless world, including the country and mobile network to which the subscriber belongs. The IMSI is one of the pieces of information stored on a SIM card.

International Mobile Equipment Identity (IMEI)

A unique number given to every single mobile phone. The number is typically found behind the battery.

Advanced Power Management (APM)

APM is an old power management tool that's rarely used anymore. In fact, only certain versions of Linux even support it. With APM, the BIOS was responsible for controlling hardware. This meant that the BIOS could do things like turn off a hard drive without the operating system even knowing. This also prevented the operating system from receiving real-time statistics about hardware components. APM had several other inherent flaws. Modern systems use a new standard called Advanced Configuration and Power Interface, or ACPI.

Preferred Roming List (PRL)

A database residing in a wireless device that contains information used during the system selection and acquisition process.

Digitizer Pad

A digitizer pad is used in laptop and PDA systems to receive input. Input is written onto the pad with a stylus pen, then those motions are transferred into data that is processed by the system. If this pad becomes scratched, the laptop or PDA cannot receive input correctly. This is most easily resolved by buying a cleaning product called Screen Clean. This product removes the top layer of plastic from the digitizer pad, thus removing existing scratches and giving the pad a fresh surface. However, you will need to replace the digitizer pad or buy a new system if the scratch is too deep.

Gyroscope

A feature that measures the vertical and horizontal orientation of the device.

MicroSD Cards

Allows mobile devices to increase their storage to upwards of 200 gigabytes.

Accelerometer

An accelerometer is also called a g-sensor. It detects a tablet's physical movements by measuring its linear acceleration in one dimension. The user interface can be automatically rotated to portrait or landscape mode, depending on the unit's orientation.

Liquid crystal display (LCD)

An electronic display system that switches pixels on and off using liquid crystals that rotate polarized light.

Mobile Storage

Another characteristic of a mobile device is its storage. In order to extend the battery life, mobile devices use some sort of non-volatile flash memory to store information. This type of memory consumes a lot less power than magnetic drives such as those found in desktop and notebook systems. Because no moving parts need to be powered, flash memory is a much more energy-efficient storage medium. In addition, a lot of mobile devices have expandable storage in the form of microSD cards. This allows mobile devices to increase their storage to upwards of 200 gigabytes.

Mobile Operating Systems

Another characteristic of mobile devices is their operating system. Unlike notebooks, which use a desktop operating system that contains mobile features, mobile operating systems are designed specifically for mobile devices and with a touchscreen interface in mind. The three most common mobile operating systems are Android, iOS, and Windows Phone. While there are several more than these three, you really need to be familiar with only these. Often, the decision between purchasing one mobile device over another is largely based on the operating system they use. The primary reason for this is that each operating system uses its own proprietary app ecosystem, which is another characteristic of mobile devices.

Tablet PC

Is a notebook that includes a touchscreen to allow input by tapping the screen, dragging objects, or through handwriting recognition. A stylus is a special pen designed to be used by these touchscreens for input. Tablet PCs might run special versions of the operating system to enable touchscreen input.

Smart Phone

Is a phone that includes functions of a PDA. As functions are added to smart phones, the line between smart phones and PDAs is disappearing.

Inverter

Is a power supply for the LCD screen that converts the DC power used by the computer to AC power needed for the backlight.

Apps

Applications must be written to run on mobile devices based on the operating system and system architecture. App distribution is provided online by platform: Google: Play Store iOS: AppStore MS: Windows Store

Portable Devices

Are built to be lighter and easier to carry. The smaller form causes components to be placed in closer proximity, which has historically caused technical development to lag behind that of desktops. Portable devices often run on battery power. Individual components are engineered to minimize the power consumption in order to maximize battery life. Because the devices are built to be carried around, they also must withstand more wear and tear.

Non-OEM or Aftermarket Parts

Are not specific to any particular notebook manufacturer and are instead created specifically as generic replacement parts. These are typically purchased through auction websites or wholesale computer parts websites. Some aftermarket parts can actually be better quality than OEM parts and are much cheaper. However, it is a bit of a gamble. You can't always be certain that the aftermarket part you purchased will be as good as the original part. Most of the time, the decision between OEM or aftermarket parts will be made by your employer, so you don't have to worry about deciding. And a lot of corporations will purchase only OEM parts. After purchasing and obtaining a new screen, you're ready to replace the bad one. Let's take a look at how this is done.

Lithium-ion or Li-ion Batteries

Are preferred for laptop use for several reasons. First, they are practically immune to the memory effect. They're also impossible to overcharge. When a lithium-ion battery reaches 100 percent charge, it simply stops charging. Lithium-ion batteries also have a very low self-discharge rate, the rate at which a battery naturally lose its charge over time. They're also much more efficient than NiMH or NiCad batteries. While lithium-ion batteries are the best choice for laptops, they do have some drawbacks. For starters, they have a slightly shorter lifespan than NiMH batteries. Lithium-ion batteries can also be damaged if the functions that prevent overcharging fail or the battery overheats, which usually results in the battery swelling. In very rare cases, thermal runaway can occur and cause the battery to catch fire or explode. To prolong the battery life and reduce the size of a laptop, many components found in a computer are either removed or combined into a single interface. For example, instead of traditional expansion slots and cards, laptops use what are called ExpressCards, which are compatible with a variety of devices.

Original Equipment Manufacturer (OEM) Parts

Are the components used by the manufacturer when building the original product. OEM parts are usually purchased directly from the manufacturer of the notebook. For example, you would purchase a replacement LCD screen for a Dell notebook directly from Dell. When purchasing an OEM part you are guaranteed that the part will work as a replacement. You also will have confidence that the part is of the same quality as the part you are replacing. However, OEM parts are a lot more expensive than aftermarket parts. Extra price doesn't always mean better quality.

Bad Backlight

Bad Backlight - A bad backlight may cause a display to become dim. It is important to note that dimming the backlight is a power saving method used by laptop computers to conserve power, so you should always verify that this isn't the cause for a dimmed screen before choosing to replace the backlight.

Video

Be aware of the following facts about screens and video cards: XGA screens have the normal 4:3 aspect ratio. WXGA screens use a widescreen aspect ratio. Some screens promise brighter display for crisper viewing or better viewing outdoors. The video controller is either integrated onto the motherboard or it might be a separate board that can be replaced. Video memory typically shares a portion of the system memory, although some notebooks have dedicated video memory. Most notebooks have an external video port that you can use to display the screen on a projector or a monitor. To show the display on the external monitor, change the display settings in the operating system or use the Fn keyboard combination. Some notebooks have special touchscreens that can rotate 180 degrees, allowing the notebook to close and the screen to still be visible. Some notebooks allow you to detach or remove the screen from the keyboard. This turns the notebook into a tablet. Some laptops have multiple display screens. You can always connect a second monitor to a laptop if you need dual display functionality.

Laptops vs Desktops

Besides their size, laptops have several key differences from desktop computers. First, laptops are designed to endure the hazards associated with traveling. They are designed to withstand some impacts and physical shock. A lot of this protection is for the laptop's hard drive. Remember, mechanical drives have moving parts, including a read/write head that floats just a few microns above a high-speed spinning platter. If the laptop were dropped or impacted while the disk was reading or writing, that read/write head would bang into the platter and ruin the drive. A second obvious difference between desktops and laptops is size. Desktops are somewhat concerned with size, but it's the driving force behind laptop design. To become more and more compact, laptops have shifted toward an integrated proprietary model. This means that a lot of the laptop's internal hardware is manufacturer-specific and contains mostly integrated parts, including integrated graphics, network cards, and sound cards. Sometimes the processor is integrated, and some laptops even integrate solid-state hard drives onto the motherboard. While this results in a smaller, more compact laptop, it does have some drawbacks. For example, if one of these integrated components failed, it's possible that the entire motherboard might need to be replaced. Another difference is power consumption. Laptops use high-capacity batteries so they can be used without being plugged in. To prolong the life of the battery, laptops use low-power components, such as special mobile processors, graphics cards, and lower spinning hard drives. The batteries that power laptops aren't your typical battery. Most consumer-level batteries lose voltage as their power drains. Because computer components require a constant, specific voltage, these batteries won't work in a laptop system. Instead, laptops use special batteries that are able to supply a constant voltage to computer components, whether the battery is charged 1 percent or 100 percent. Over the years, laptops have used three different types of batteries that supply a constant voltage. So, those are the differences between laptop and desktop computers. Remember, laptops are designed to be portable. As such, they often use proprietary and integrated components to achieve smaller sizes and lower power usage. They also use lithium-ion batteries to provide mobile power. Laptops also combine multiple functions into a single port, such as an ExpressCard port or a Thunderbolt port. Most notebooks use thin 2 1/2-inch drives. Desktops, on the other hand, typically use the thicker 3 1/2-inch drives. In addition, instead of having to connect individual cables, notebook drives simply slide into the drive bay and the power and SATA connections are made.

Netbook

Is a notebook computer with a smaller form factor (10-11 inch screen or smaller) and custom hardware designed to maximize battery life (from 6-11 hours on a single charge). Originally, netbooks used a special operating system that often did not support all of the features of a normal desktop operating system. Increasingly, netbooks can run a regular version of the operating system, although the reduced hardware might still limit their usefulness to email, word processing, and multimedia. Netbooks typically do not have integrated CD/DVD drives.

Pointing Devices

Instead of a mouse, notebooks use one (or more) of the following devices: Pointing sticks are small knobs in the center of the keyboard. Pushing on this knob moves the cursor. The touchpad is located below the keyboard. Moving your finger across the pad moves the mouse. You can also tap the touchpad to click the mouse. Buttons below the keyboard replace mouse buttons for clicks, double-clicks, and right-clicks. A digitizer pad is used in laptop and PDA systems to receive input. Input is written onto the pad with a stylus pen and then those motions are transferred into data that is processed by the system. You can also use the PS/2 connector or a USB connector to connect an external mouse. Touchpads are more common than pointing sticks. Notebooks with a pointing stick often come with a touchpad as well.

Dead Spots

Dead Spots - Dead spots are areas on your screen (sometimes entire rows or columns of pixels) that no longer work. This means that your LCD assembly is no longer functioning and you will need to replace it. Be aware that it is often cheaper to purchase a new laptop computer than to replace the display.

Accelerometer

Detects the physical movements of the tablet by measuring its linear acceleration in one dimension.

Internal hard disks

Internal hard disks are typically 2.5" or 3.5" and very thin compared to desktop hard disks. SATA, solid state drives, and Flash drives are used in portable devices.

Power Scheme

Is a collection of power settings that are either predefined or created by a user for use in different computing environments.

Personal Digital Assistant (PDA)

Is a hand-held device, typically with a small touchscreen. A PDA uses special hardware and software that provides basic productivity applications (email, word processing, spreadsheets).

E Ink

E Ink is a special technology that creates a high-contrast black-and-white display. Even though they can only display grayscale, E Ink screens are great for e-readers because they consume much less power than LCD screens and they don't suffer from visibility problems when used in bright sunlight.

E-Readers

E-readers are similar in size to tablets, but they lack the functionality of a tablet. Their primary purpose is for reading digital books, newspapers, magazines, and other periodicals. Most e-readers use E Ink to display digital content.

E-readers

E-readers are similar in size to tablets, but they lack the functionality of a tablet. Their primary purpose is for reading digital books, newspapers, magazines, and other periodicals. Most e-readers use E Ink to display digital content. E Ink is a special technology that creates a high-contrast, black and white display. Even though they can display only grayscale, E Ink screens are great for e-readers because they consume much less power than LCD screens and they don't suffer from visibility problems when used in bright sunlight.

Fn Key (short for function)

Is a keyboard modifier key that allows the keyboard to perform additional functions without needing to add additional keys. The Fn key is typically found on notebooks (because of their compact keyboard design) and on full-sized multimedia keyboards. Keys that have a special function when pressed in conjunction with the Fn key can be identified by a small icon or word, which is typically the same color as the Fn key. For example, the F1 key on a notebook might have a small moon icon in the corner of the key, indicating that the Fn+F1 key combination will put the notebook to sleep.

Dim Display

First, check the brightness setting. The brightness setting on a notebook system is usually controlled by pressing a function key combination. It's not uncommon for an user to accidentally hit the wrong keystroke combination, dimming their display. Check the system documentation to determine the appropriate keystrokes to adjust the brightness. If the system uses an LCD display, then it's also possible that the inverter has failed. Remember, an LCD panel needs to be illuminated to see the display. That's accomplished by the backlight, which is a small fluorescent light that runs on AC power. The inverter is located inside of the bezel and it converts DC power from the notebook to AC power to run the backlights. If the inverter fails, the backlight goes out and the display dims or flickers. Replacement inverters are widely available at a reasonable price on the internet. It's also possible that the backlight itself has failed. If this happens then it needs to be replaced. These are also widely available on the internet for a reasonable price.

Flickering Screen

Flickering Screen - A flickering screen can be caused by a faulty backlight or inverter. Replacement parts can be purchased from your laptop's manufacturer.

Flickering Display

If the system uses an LCD panel then the flickering may be caused by a failing inverter. If the inverter isn't supplying sufficient power to the backlight, the backlight may flicker. If this is the case, then the inverter should be replaced. It could also be caused by a failing backlight. Again, this will require the backlight to be replaced. It's also possible that a flickering display is being caused by a failing display panel. If this is the case, then it'll need to be replaced. No External Display The last display related issue we need to discuss is one where you can't send the display to an external monitor. This usually isn't a problem with the system hardware, it's usually just a configuration error on the part of the user. If you can't send the display to an external monitor check the following: Verify that the video cable is actually connected to the right video port on both the notebook system and on the external monitor. Verify that the display is being sent to the correct external port. Some notebooks have multiple external video ports such as VGA and HDMI. If this is the case, make sure that you're sending the output to the right port. Verify that the external monitor is configured to accept input on the correct input port.

Working State

In this state, you can use the entire system, and hardware that's not used can enter a lower power state to save energy.

Trackpad (Touchpad)

Is the notebook's mouse. It uses technology similar to a touch screen to detect finger movements and move the cursor. It also has a left and right button for left-click and right-click actions. Some notebooks have a toggle switch near the track pad to enable or disable it. For example, if you plug in a USB mouse, you probably want to disable the track pad. Sometimes people forget to enable the track pad after disabling it. They may call you saying their track pad isn't working. If this happens, the first place to check is the track pad on/off switch.

Sticky Keys

Is when you press a key down it doesn't come back up or you have to push down extremely hard to get the key to depress all the way. Usually a sticky key is caused by debris underneath the key. The debris prevents the key from either going down or coming back after it's been depressed. The best way to clean the keyboard is to use compressed air or a soft brush. Never use water to clean the keyboard, this will damage the keyboard and possibly other system components. If necessary, you can physically remove the keyboard from the system so that you can clean it more effectively.

Advanced Configuration and Power Interface (ACPI)

It allows the OS to communicate directly with hardware components and discover, configure, monitor, and manage power. Is the operating system that desktop and notebook systems use.

Ghost Cursor/Pointer Drift

It could be caused by misconfigured touchpad sensitivity settings in Control Panel. If this is the case, just modify the sensitivity settings. It could also be caused by a malware infection. If you suspect that this is the case run a full scan with your antivirus software. Another problem you might run into is cursor drift. In this situation, the cursor moves across the screen on its own, with or without the user touching the touchpad. This could be caused by several issues. The drivers for the touchpad may be corrupt or outdated. Try downloading and installing the latest drivers from the notebook vendor's website. If a secondary external mouse has been connected such as through a USB port then the touchpad and the mouse may be conflicting with each other. For some notebooks you can access the BIOS or UEFI setup for the system and disable the touchpad if an external mouse is connected. For others you may need to use a software utility from within Windows to disable the touchpad if a mouse is connected. Maybe the touchpad itself or its connectors are malfunctioning. If you have a known good touchpad you can try replacing the suspect touchpad with a working one and see if that fixes the problem.

Physical Lock Slot

It is used to physically secure the notebook to a location. It accepts a special cable lock. One end of the cable locks to the notebook using a key. The other end of the cable is locked to a physical structure, such as a desk.

Memory

Laptop memory uses SODIMM and UniDIMM packages with SDRAM and DDR/DDR2/DDR3/DDR4 memory. These modules are sometimes called MicroDIMMs. Many notebooks come with a base amount of memory built onto the motherboard and one or two additional slots. When replacing notebook memory, make sure the size of modules you purchase are supported by the system.

Missing Keys

Many notebook manufacturers design the keyboard to use breakaway keys. If you can find the missing key, it can usually be reattached by simply pressing it back into place until you hear a click. Once done, it should remain in place. If you can't find the missing key you'll need to purchase a replacement keyboard.

Internal Sensors

Mobile devices also have internal sensors that collect environmental data. A common example of this is a GPS chip. Mobile devices use GPS chips to calculate the device's location information. This is helpful for things like navigation applications and device location services. Another internal sensor that mobile devices use is called an accelerometer. An accelerometer is a sensor that detects movement on a single plane. In mobile devices, this is typically the horizontal plane. This is the sensor that detects when a mobile device is turned sideways and tells the device to change the screen's orientation. A third sensor used by mobile devices is called a gyroscope. A gyroscope also detects movement, but it does so a bit differently than an accelerometer. Instead of detecting movement on a single plane, a gyroscope detects horizontal and vertical movements. If you've ever played a game on a smartphone or tablet that requires you to tilt the device, then you've used a gyroscope.

Wireless Features

Mobile devices need to be able to have mobile connectivity to the internet and other types of mobile devices. To do this, mobile devices use a variety of wireless connection mediums. For example, the typical smartphone uses 802.11, Bluetooth, and cellular wireless technologies. Some mobile devices might use only 802.11 wireless or Bluetooth, but a lot of mobile devices use multiple wireless mediums.

Networking

Most notebooks include built-in networking devices such as an Ethernet port, a modem port, wireless, Bluetooth, and/or infrared. Wireless networking capabilities are often provided by a small card that plugs into an internal mini-PCI slot (located under the keyboard or accessible through the back). The wireless antennae might be a wire that extends around the screen. You can use USB or ExpressCards to add missing or malfunctioning networking features.

Mouse Malfunction

Mouse malfunction on a laptop is usually caused by the installation of an incorrect driver. Good indicators that the incorrect driver has been installed are if the laptop mouse's sensitivity isn't consistent or if the mouse doesn't recognize a double tap.

Active Hard Drive Protection

The hard drive contains a system of accelerometers that are able to detect sudden movements or vibrations, which indicate an impact is going to occur. When an event is detected, the hard drive unloads the read/write head so it doesn't damage the platter.

Nickel-Cadmium or NiCad Batteries

NiCad batteries were used in original laptops. They worked well for their time, but they have several serious issues. First, NiCad batteries are susceptible to damage from overcharging. Accidently charging a NiCad battery beyond 100 percent will damage the battery cells. Second, NiCad batteries suffer from a problem known as the memory effect. This occurs when the battery is recharged at the same point over and over again. For example, if you were to charge a NiCad battery to 100 percent every time it reached 50 percent charge, the battery would start to think that a 50 percent charge means a 0 percent charge. This causes the voltage level to drop at 50 percent instead of at zero, essentially halving the battery's capacity. Another huge drawback is the fact that NiCad batteries contain highly toxic materials that have severe environmental impacts if they're not disposed of properly.

Keyboard

Notebook keyboards are smaller than standard keyboards. Keys are often a bit smaller and closer together. Keys such as the number pad and some function keys might be left off, but are accessible by pressing a special Fn key to provide alternate functions for regular keys. You can use a USB port to connect an external keyboard; some laptops include a PS/2 port.

Network Power Issues

Notebook power issues are quite different from the power issues on desktop systems. Let's first discuss situations where there is no power being provided to the notebook. This is a common issue. The AC adapters used with notebook systems tend to fail after a few years. You can verify this by testing the DC side of the adapter with a voltmeter. Then, compare this with the rating listed on the bottom of the AC adapter to verify that it's producing the correct voltage. If it's not, replace the AC adapter with a new one. Replacement AC adapters are widely available on the Internet. Those purchased from the laptop manufacturer will provide the best performance and last the longest. However, they'll also be considerably more expensive than aftermarket AC adapters. You may also encounter situations where the notebook system is not getting power because the DC connector within the notebook system itself is broken. This is a less common issue but it does happen. These connectors can usually be replaced but it will require soldering to do so. If you haven't been trained how to solder, especially very small motherboard connectors, you should probably just purchase a new motherboard. Another common power issue with notebooks is a battery that fails to charge. This could be caused by several things. It could be caused by a failed AC adapter. Use a voltmeter on the DC side of the adapter to test the voltage it's producing. If it's less than what the adapter is rated to produce then you should replace the AC adapter. This problem could also be caused by a failed battery. Remember, a notebook battery has a limited number of discharge cycles. The more you charge and discharge the battery, the sooner it's going to fail. If the battery run time has been getting shorter and shorter it will need to be replaced. As with replacement AC adapters, replacement notebook batteries are widely available on the Internet. Those purchased from the notebook manufacturer will likely last the longest but will also cost considerably more than those provided by a third-party manufacturers.

Unresponsive Touchpad

Notebook touchpads tend to collect debris over time such as dead skin, oil, and spilled liquids. To keep the touchpad functioning properly you should clean it regularly. Don't use water, just use a clean, soft rag.

Phablets

Phablets aren't as small as a smartphone and aren't as powerful as a tablet. They're somewhere in between. Phablets usually have a screen size between 5.2 inches and 7 inches. In fact, any smartphone with a screen bigger than 5.2 inches is technically a phablet, not a smartphone. Most phablets are able to use special stylus pens to interact with the device. This allows for more accurate screen tapping for things like writing notes, drawing diagrams, or navigating apps.

Due to the integrated nature of laptops, troubleshooting laptop components is significantly harder than troubleshooting desktop components. Most laptop manufacturers provide service manuals on their websites that you can use to learn specific troubleshooting procedures for a particular make and model. The following table provides some general troubleshooting guidelines to follow when working with laptop computers:

Power Laptops can run from either AC power through the transformer or from battery power. When troubleshooting power, verify that: The cord from the AC outlet to the power adapter is correctly plugged into both the wall and the adapter unit. Move it around to see if a more secure connection can be made. The LED light on your power adapter is lit. If it isn't lit, this means that your point of failure is between the outlet and the adapter. Your battery is sufficiently charged. If the battery reads it is fully charged in Windows, disconnect your laptop from its power source. If the battery lasts only a short amount of time, you can assume that your battery needs to be replaced. If the computer runs for only a short time even while plugged in, it could be that the power adapter is bad. If the adapter is not working, the computer will run off of the battery until the battery is drained. Try using a different adapter, or verify the power coming from the adapter. If your battery seems to be losing the ability to hold a charge, or if the power drops shortly after starting to use it, you might need to recalibrate the battery. Video If your laptop has no display at all, Press the Fn (Function) and the appropriate display key to switch the display output to the laptop monitor. If the built-in monitor isn't working, connect an external monitor to the laptop. Use the Fn keys to direct output to the external monitor. If you don't get a display on either monitor, you can assume that there is a problem with the video card. Repairing the video card typically means replacing the motherboard. If the display renders on the external monitor but still won't render on your laptop, then you can assume that there is a problem with your LCD display. If this is the case, you should verify that: Your LCD cutoff switch is working. Sometimes the switch can get stuck in the off position, thus preventing the display from being sent to the LCD. There aren't cracks in the bezel around your LCD. This can be an indicator that your LCD has been damaged. The power bundles that go from your laptop to the LCD are not damaged or cracked. You must remove the bezel around the LCD to inspect the power bundles. Additional problems with laptop displays include: Dead Spots - Dead spots are areas on your screen (sometimes entire rows or columns of pixels) that no longer work. This means that your LCD assembly is no longer functioning and you will need to replace it. Be aware that it is often cheaper to purchase a new laptop computer than to replace the display. Bad Backlight - A bad backlight may cause a display to become dim. It is important to note that dimming the backlight is a power saving method used by laptop computers to conserve power, so you should always verify that this isn't the cause for a dimmed screen before choosing to replace the backlight. Flickering Screen - A flickering screen can be caused by a faulty backlight or inverter. Replacement parts can be purchased from your laptop's manufacturer. If you know that your LCD needs to be replaced but you don't have the resources to buy a new LCD or a new laptop, you can consider converting your laptop into a desktop system by hooking it up to an external monitor permanently. If the video card is bad, you might be able to use a remote solution, such as Remote Desktop, to connect to the laptop from an external system. Applications If you cannot load an app from the Microsoft Store, use the Windows Store Apps Troubleshooter to search for and correct problems. Third-party apps have varying levels of support. You may have to contact the developer to troubleshoot issues. If you are unable to decrypt an email, you probably do not have the correct private key. You will need to export it from another computer. If your GPS is not functioning, begin troubleshooting by running the Hardware and Device Troubleshooter program. You can also update Bluetooth drivers if you are having trouble pairing a GPS-dependent Bluetooth device. If the pairing device uses Window 7 or older, install the drivers in Compatibility mode for the correct Windows version. And as always, use known good devices to check for damaged hardware and replace components as necessary. Laptop Components The most common portable components used with laptop systems are keyboards, mice, digitizer pads, and antennae. The following list suggests troubleshooting methods to use when working with these components: A bad keyboard can be tested by plugging in an external keyboard to your laptop and seeing if it works. If it does, you can assume that your laptop keyboard is malfunctioning and needs to be replaced. Most laptop systems have features that cause keyboard keys to perform alternate functions, such as emulating 10-key functionality by turning on the NUM LOCK. Before troubleshooting other problems, make sure that no special features are enabled that may cause keys to perform alternate tasks. Sometimes the NUM LOCK indicator lights don't correctly correspond to the NUM LOCK's function state. Some power saving modes don't support indicator light function. Sometimes you must press the F LOCK key with the NUM LOCK key for it to respond. If neither of these is the case, the computer probably isn't properly maintaining the NUM LOCK state and may have damaged components. Mouse malfunction on a laptop is usually caused by the installation of an incorrect driver. Good indicators that the incorrect driver has been installed are if the laptop mouse's sensitivity isn't consistent or if the mouse doesn't recognize a double tap. A digitizer pad is used in laptop and PDA systems to receive input. Input is written onto the pad with a stylus pen, then those motions are transferred into data that is processed by the system. If this pad becomes scratched, the laptop or PDA cannot receive input correctly. This is most easily resolved by buying a cleaning product called Screen Clean. This product removes the top layer of plastic from the digitizer pad, thus removing existing scratches and giving the pad a fresh surface. However, you will need to replace the digitizer pad or buy a new system if the scratch is too deep. Another problem that digitizer pads face is called pointer drift or ghost cursor. Drift occurs when a pad's pressure sensors need to be realigned. If this is the case, your digitizer pad needs to be recalibrated. It is always best to address this issue before it progresses to the point that you can't access the recalibration utility. Though laptop antennae are supposed to be omni-directional, they sometimes need to be re-oriented to get the best reception. This can usually be done by moving the laptop until the reception picks up. If redirecting the antennae doesn't work and wireless reception is consistently poor, the antennae may need to be replaced. Many laptops include a switch that turns the wireless network card on and off. When troubleshooting wireless network connectivity, make sure the switch is turned on. If your speakers are not producing sound, begin troubleshooting by making sure the volume is turned all the way up and your speakers or headphones are connected correctly. Make sure your sound card works properly and is running with updated drivers. If that doesn't fix the issue, run the Windows Audio Troubleshooter program. If none of these solutions work, you may have damaged hardware components that need to be replaced. As long as your laptop runs, you can substitute an external device connected to a PS/2, USB, PCMCIA, or ExpressCard slot for most failed components, allowing you to continue using the computer.

Processor

Processors built especially for laptop computers have lower power consumption requirements and produce less heat than desktop processors. On most systems, you can configure the processor to use a lower bus speed when running from battery power, thereby conserving battery life. Many mobile processors are capable of automatic throttling to turn off extra cores or reduce the speed to conserve energy. Processors do not have the large heat sink and fan combinations to dissipate heat. Rather, heat is controlled by minimizing power consumption and small fans that draw away heat.

Smart Phones

Smart phones combine the functionality of a cellular phone with the features of a desktop computer. Smart phones can access the internet either through a Wi-Fi connection or by using a 3G, 4G, and LTE cellular connection. They can also be used as a GPS navigation unit, a portable gaming device, and a mobile music player. Smart phones typically have a screen size between 2.5 inches and 5 inches. Most smart phones use the Android and iOS operating systems, but there is also a Microsoft Windows system called Lumia and a Google Chrome operating system called Fuchsia.

Smartphones

Smartphones combine the functionality of a cellular phone with the features of a desktop computer. When they were first developed, smartphones really were limited in their functionality. However, smartphones have since become some of the most powerful and versatile mobile devices. Smartphones are able to access the internet either through a WI-FI connection or by using a 3 or 4G cellular connection. They can also be used as a GPS navigation unit, a portable gaming device, and a mobile music player. Smartphones typically have a screen size between 2.5 inches and 5 inches.

Backlight

The light that illuminates an LCD screen so that images on the screen are visible.

App Ecosystem

Software programs that run on mobile devices are called apps. Mobile devices must use apps that have been written specifically for their particular mobile operating system. This means an app written for an android won't be able to run on iOS and vice versa. Because of this, each mobile OS has its own app ecosystem. This is a fancy way of referring to the apps that a particular mobile OS has available to it. For example, iOS uses the iOS App Store, Android uses the Google Play Store, and Windows Phone uses the Windows Phone Store. Like most things, each app ecosystem has pros and cons that are largely opinion-based. The main thing to know is that when you purchase a particular mobile device, you are buying into a specific app ecosystem. One final thing you should be aware of regarding mobile devices is that most of the internal hardware components are non-serviceable. This means that if the processor fails, you have to purchase an entirely new device. It's not even possible to replace a faulty battery in some mobile devices. This touches on the fact that mobile devices are not designed as a complete solution. They are instead designed to be a supplement to other computing devices. While they do have a lot of functionality and do a lot of things really well, they have their limitations.

Tablets

Tablet devices use a touchscreen interface instead of the touchpad and keyboard used by notebook PCs. The touchscreen interface is usually capacitive, meaning that it requires conductive material, such as your finger tip, for input. Capacitive touchscreens provide multi-touch capabilities, which allow the tablet to recognize multiple finger touches at the same time.

Tablets

Tablets were some of the first types of handheld mobile devices. They typically have more computing power than smartphones, but are also much larger and more expensive. A typical tablet screen size is between 10 inches and 15 inches. Tablets are designed as a type of notebook replacement. While they aren't as powerful as a notebook system, they tend to be more portable, have a longer-lasting battery, and have much of the same productivity tools available to them. Most tablets can even connect to a wireless keyboard to allow for easier typing.

No Display

The first issue is one where no output is visible on the notebook display. There are several different possible causes. The system might be configured to use an external video port, VGA or HDMI, instead of the built-in display. If this is the case, check the system documentation to find out how to switch the output back to the built-in display. A blank display could also be caused by a disconnected video ribbon cable that connects the display panel to the display adapter on the motherboard. If this is the case, you need to disassemble the notebook and reconnect the cable. Be sure to verify that both ends are properly secured. Blank output could be caused by a failed display panel. Display panels tend to fail over time, especially LCD display panels. If this happens, disassemble the system, remove the display panel from the bezel, and replace it with a new one.

ACPI Power States

Working Standby Sleep Hybrid Sleep Hibernate Soft Off Mechanical Off

Touchscreens

The most common characteristic of a mobile device is its touchscreen. Because mobile devices are designed to be extremely mobile, they typically don't use peripheral devices. Instead, mobile devices use capacitive touchscreens to receive user inputs. The reason mobile devices use capacitive touchscreens as opposed to resistive touchscreens is because capacitive touchscreens are able to detect multiple contact points. For example, being able to zoom in on a photo using two fingers is possible only because of the capacitive touchscreen. The one drawback is that capacitive touchscreens require a conductive object to touch the screen. A gloved hand won't be able to manipulate the screen. Some mobile devices are also capable of using a special stylus to interact with the device. The stylus looks very similar to a pencil or pen, but has a special tip that allows you to draw, write, or interact with the device much more accurately than is possible with a finger.

Android Package (APK)

The package file format used by the Android operating system for the distribution and installation of mobile apps and middleware.

Bezel

The plastic casing around an electronic device's screen.

Hibernate State

The system appears to be off, and power consumption is reduced to the lowest level. Volatile memory is saved to a hibernation file to preserve the system state. The computer can wake from input from the keyboard, LAN, or a USB device, and the working context is restored if it's stored in nonvolatile media.

No Wireless Connectivity

The wireless adapter is shut off using an external switch. Users can accidentally hit that switch causing the wireless connection to go down. Verify that the correct drivers for the wireless adapter have been loaded. Also check to see if updated drivers are available. Verify that the wireless adapter is configured correctly. It must be configured to use the correct SSID, security type, and pass phrase for the wireless network. Also verify that it's been configured with the correct IP addressing information for the subnet. The wireless access point may be out of range. The farther away the notebook system is from the wireless access point the weaker the radio signal will be. If the signal falls below a certain threshold then the wireless adapter will not associate with the access point. If this happens, move the notebook system closer to the access point. If this isn't an option, consider implementing additional access points. EMI can cause connectivity problems. EMI can disrupt the radio signal used for a wireless network. This can be caused by electrical equipment, microwave ovens, wireless phones, or neighboring wireless networks. If this happens, you can try installing shielding around EMI emitters. If the interference is being caused by a neighboring Wi-Fi network, make sure your network and the neighboring network are using a different channel. This can be problematic for 2.4 GHz wireless networks as there are only 3 non-overlapping channels, 1, 6, and 11. For 5.8 GHz networks this is less of an issue as there are many more channels to choose from.

SD Card Reader

This can be used to retrieve data from an SD card. Also there may be status LEDs. Examples of status LEDs are HDD LED, Caps Lock, and integrated wireless network card.

Screen Clean

This product removes the top layer of plastic from the digitizer pad, thus removing existing scratches and giving the pad a fresh surface. However, you will need to replace the digitizer pad or buy a new system if the scratch is too deep.

Standby State

This state lets the system switch from a low-power state to a high-power state very quickly so it can respond to hardware or network events.

Wearable Devices

Wearable devices are a type of mobile device meant to be worn somewhere on the body. These devices range from being as simple as a fitness tracker wrist band to as complex as glasses or a virtual reality headset. Most wearable devices are designed to interface with another device. For example, a smart watch by itself has a limited set of functionality; however, smart watches are designed to connect to smart phones using Bluetooth. Doing this unlocks additional functionality, such as reading texts or answering phones calls through the smart watch.

Wearables

Wearables are a type of mobile device that is meant to be worn somewhere on the body. These devices range from being as simple as a step-tracking wristband to as complex as a virtual reality headset. Most wearable devices are designed to interface with another device. For example, a smartwatch by itself has a limited set of functions. However, smartwatches are designed to connect to smartphones using Bluetooth. Doing this unlocks additional functionality, such as reading texts or answering phone calls through the smartwatch.

Webcam

Webcams are camera and microphone systems that allow users to communicate through the internet with audio and video. Most laptops have a built-in webcam, but you can purchase one and connect it to the computer through a USB port.

Sleep State

When a system is in a Sleep state, it looks like it's off, but volatile memory is refreshed, and some components remain powered so the computer can quickly wake up when it receives input from the keyboard, LAN, or a USB device.

Soft Off State

Where the system appears to be off and the state is comprised of a full shutdown and boot cycle. And the last state is Mechanical Off, where the system is completely off and consumes no power, and it only returns to a working state after a full reboot.

Mechanical Off State

Where the system is completely off and consumes no power, and it only returns to a working state after a full reboot.

Hybrid Sleep State

Where the system uses a hibernation file to save the system state in case there's a power outage.

Mobile Device Power

Whether it's a tablet, smartphone, or an e-reader, all mobile devices share some common characteristics. The most common is its power source. As their name implies, mobile devices need to be mobile. This means they need to have some sort of mobile power source. This source is typically a lithium ion battery. Lithium ion batteries are rated in milliamp hours. The larger the number, the greater the battery capacity. For example, the average smartphone battery is about 2,000 milliamp hours. A notebook battery is about 6,000 milliamp hours.

Operating System-directed configuration and Power Management (OSPM)

With ACPI, hardware configuration settings are only controlled by the operating system. The operating system receives real-time statistics about how much power each hardware component is using. Then it uses this information to decide whether it should leave it alone, reduce the amount of power it's consuming, or shut it down entirely.

Number Lock Key is turned on

You may also run into problems where the NUM LOCK key has been turned on. Most notebook systems don't have a 10 keypad. Instead they emulate a 10 keypad using standard QWERTY keyboard. If the NUM LOCK key gets pressed accidentally then the QWERTY keyboard types numbers instead of letters, usually with the right hand. If this happens, see if the user accidentally enabled the NUM LOCK key.