Chapter 24 Portable Computing (220-901)

Input Devices
Portable computers come with a variety of input devices. Most have a fully functional keyboard and a device to control the mouse pointer.
Keyboard Quirks
Laptop keyboards differ somewhat from those of desktop computers, primarily because manufacturers have to cram all the keys onto a smaller form factor. Almost every portable keyboard uses a Function (FN) key to enable some keys to perform an extra duty. You’ll note that the latter has no separate number pad on the right. To use the number pad, you press the FN key (lower left in this case) to transform the (7,8,9), (U,I,O), (J,K,L), and (M) keys into the (7, 8, 9), (4, 5, 6), (1, 2, 3), and (0) keys.
Pointing
Portables need a way to control your mouse pointer, but their smaller size requires manufacturers to come up with clever solutions. Early portables used trackballs. Trackballs are just a mouse with a ball on it to control the PC.

The next wave to hit the laptop market was IBM’s TrackPoint device, a joystick the size of a pencil eraser, situated in the center of the keyboard. You use a forefinger to push the joystick around, and then click or right-click, using two buttons below the speaker.

The touchpad is a flat, touch-sensitive pad just in front of the keyboard. To operate a touchpad, you simply glide your finger across its surface to move the pointer, and tap the surface once or twice to single- or double click.

Some manufacturers today include a multitouch touchpad that enables you to perform gestures, or actions with multiple fingers, such as scrolling up and down or swiping to another screen or desktop. The Multi-Touch on Apple’s laptops pioneered such great improvements to the laptop-pointing-device experience that the lack of a mouse is no longer a handicap on many laptops.

Touchscreens can also be a pointing device. Kind of like smartphones or tablet.

Webcams and Microphones
The ability to communicate with others through real-time video is such a common expectation of mobile and portable devices these days that most of these devices come equipped with some sort of front-facing video camera, a webcam in the case of laptops, and one or more built in microphones.
Display Types
Laptops come in variety of sizes and at varying costs. One major contributor to the overall cost of a laptop is the size of the LCD screen. Most laptops offer a range between 10.1-inch to 17.3-inch screens, while a few offer just over 20-inch screens.

In the past, 4:3 aspect ratio screens were common, but these days it is hard to find one on anything but special purpose or ruggedized laptops; all most all regular laptops come in one of two widescreen format ratio. Aspect ratio is the comparison of the screen width to the screen height. While widescreens can have varying aspect ratio, almost all of the screens you find in present day laptops will be 16:9 or 16:10.

Laptops LCD screens come in variety of supported resolutions, described with acronyms such as XGA, WXGA, WSXGA, and more. The W in front of the letters indicates widescreen.

Laptop screens typically come with one of two types of finish: matte or high-gloss. The matte finish was the industry standard for many years and offered a good trade-off between richness of colors and the reduction of glare. The downside of using a matte finish laptop is that they wash out a lot in bright light.

Manufacturers released high-gloss laptop screens 2006, and they rapidly took over many store shelves. The high-gloss finish offers sharper contrast, richer colors, and wider viewing angles when compared to the matte screens. The drawback to the high-gloss screen is that they pick up lots of reflection from nearby objects.

As with other LCD technologies most LCD/LED screens use twisted nematic (TN) technology. Some laptop screens use In-Plane Switching (IPS) panels for the greater viewing angle and better color quality. You will mostly find IPS panels on higher-grade portables.

What you will not find on portables are two other display technologies, plasma and organic light-emitting diode (OLED). Plasma displays demand a lot more electricity than LCDs demand and are completely inappropriate for portable devices. OLED screens sip energy when compared to LCDs, but they are still so expensive that you will only find them on smartphones and tablets today.

Single-Function Ports
All portable computers come with one or more single-function ports. You’d have a hard time finding a portable computing device that doesn’t have an audio port, for example. Laptops often provide a video port for hooking up an external monitor, though wireless screen sharing and screencasting are gaining popularity as an alternative.

Ports work the same way on portable computers as they do on desktop models. You plug in a device to a particular port and, as long as the OS has the proper drivers, you will have a functioning device when you boot.

Audio
Portable computers have a standard 3.5-mm audio-out port and some have a similarly sized microphone-in port, though built-in microphones are increasingly common. You can plug in headphones, regular PC speakers, or even a nice surround sound to set to enable the laptop to play music just as well as a desktop computer can.
Display
Most laptops support a second monitor via a digital port of some sort. There are many of these, you will find HDMI (including Mini-HDMI, and Micro-HDMI), Display port (including USB Type-C and Thunderbolt), and DVI; on ancient or special purpose portables, there is even a chance to find an analog VGA. With a second monitor attached, you can duplicate your screen to the new monitor, or extend your desktop across both displays, letting you move windows between them.

Most portables use the FN key plus another key on the keyboard to cycle through display options

You can control how the external monitor displays through the Display applet in the Control Panel in Windows. Open Display and click on “Change display settings”. On the Screen Resolution panel, click the drop-down arrow next to Multiple displays. You will see several options, “Extend these displays” makes your desktop encompass both the laptop ad the external monitor. “Duplicate these displays” places the same thing on both displays.

Smart Card Reader
A smart card reader can be used for security purposes to ensure that a trusted user is using the laptop.
802.11 Wireless
Most portables today have Wi-Fi directly into the chipset for connecting the device to a wireless access point (WAP) and from there to a bigger network, such as the Internet. The 802.11b and 802.11g standards are common on older laptops; newer portable computers use 802.11n or 802.11ac
Bluetooth
Most portables have a functional Bluetooth as well. Bluetooth gives you the ability to add wireless peripherals such as mice, keyboards, and headsets, as well as communicate with smartphones, speakers, and other Bluetooth devices.
Hardware Switches
Portable computers that come with wireless technologies such as 802.11, mobile broadband, GPS, or Bluetooth have some form of on/off switch to toggle the antenna off or on so that you may use the laptop in areas where emissions aren’t allowed. The switch may be hard wired or it may be a toggle of the FN key plus another key on the keyboard.
Wired Ethernet
Most full-size laptops have an Rj-45 wired Ethernet connection. These work exactly like any other Ethernet jack, they have link lights and connect via UTP cable. Be aware, however, that wired Ethernet is one of the things hybrids, Ultrabooks, and other smaller portables usually leave out.

There are two issues with RJ-45s on laptops. First they do not have an off/on switch like the 802.11 and Bluetooth connections. You can turn them off just like you would turn off the NIC on a desktop: disable the NIC in Device Manager or turn the NIC off in BIOS.

Portable-Specific Expansion Slots
The makers of portable computers have developed methods for you to add features to a portable via specialized connections known generically as expansion slots. For many years the PCMCIA established standards involving portable computers, especially when it came to expansion cards and slots. Once a common feature on laptops, these specialized expansion slots are almost impossible due to the dominance of USB. The last standard was called ExpressCard.
ExpressCard
ExpressCard comes in two widths: 34 mm and 54 mm, called ExpressCard/34 and ExpressCard/54.

ExpressCards connect to either the USB 2.0 or the PCI Express bus. These differ a lot in speed. The USB 2.0 connection has a max speed of 480Mbps and PCIe has a max speed of 2.5Gbps.

PCMCIA announced ExpressCard 2.0 in 2009 with speeds up to 5 Gbps and support for SuperSpeed USB 3.0, we expected to see more to come but instead PCMCIA shut down its offices and there has not been any further development for ExpressCard.

Storage Card Slots
Many portable computers offer the option for an SD card reader
General-Purpose Ports
Portable computers rarely come with all of the hardware you want. Today’s laptops usually include at least USB ports to give you the option to add more hardware. Some special purpose laptops may still provide general-purpose expansion ports for installing peripheral hardware, while other portables focus on more modern ports like Thunderbolt, eSATA, and FireWire.
USB, Thunderbolt, FireWire, and eSATA
Universal serial bus (USB), Thunderbolt, FireWire (IEEE 1394), and eSATA enable users to connect a device while the PC is running, no need to reboot. Because portable computers have don’t have a desktop’s multiple internal expansion capabilities, USB, Thunderbolt, FireWire, and eSATA are some of the more popular methods for attaching peripherals to laptops.
Docking Stations
Docking stations offer legacy and modern single-and multi-functional ports. The typical docking station uses a proprietary connection but has extra features built in, such as an optical drive or ExpressCard slot for extra enhancements. You can find docking stations for many older small laptops. A docking station makes an excellent companion for portables.
USB Adapters
When you do not need access to a number of ports at once, you can often find a USB adapter for whatever you need to connect.

Two great examples of this are wired Ethernet and optical drives. A USB to RJ-45 dongle and a USB optical drive can provide these features when and where I need them.

Another good use for USB adapters is updating connectivity support for older devices. A USB to Wi-Fi dongle or a USB Bluetooth adapter can let me update an old laptop to 802.11ac, or add Bluetooth to a laptop that didn’t come with it built in.

Batteries
Manufacturers over the years have used a few types of batteries for portable computers: Nickel-Cadmium (Ni-Cd), Nickel-Metal Hydride (Ni-MH), and Lithium Ion (Li-Ion). Today, only Li-Ion is used because that battery chemistry provides the highest energy density for the weight and has few problems with external factors.
Lithium-Ion
Li-Ion batteries are powerful, and last much longer that the Ni-MH and Ni-Cd ones we used in the 1990s. If Li-Ion batteries have a downside, it’s that they will explode if overcharged or punctured, so all Li-Ion batteries have built-in circuitry to prevent accidental overcharging. Lithium batteries can only be used for systems designed to use them. They can’t be used as replacements batteries to keep that retro laptop from 1998 going.
The Care and Feeding of Batteries
In general, keep in mind the following basics. First, always store batteries in a cool place. Second keep the battery charged, at least to 70-80 percent. Third, never drain a battery all the way down unless required to do so as part of battery calibration.

Rechargeable batteries have only a limited number of charge-discharge cycles before overall battery performance is reduced. Fourth, never handle a battery that has ruptured or broken; battery chemicals are very dangerous and flammable. Finally, always recycle old batteries.

Power Management
Many different parts are included in the typical laptop, and each part uses power. The problem with early laptops was that every one of these parts used power continuously, whether or not the system needed the device at that time. For example, the hard drive continued to spin even when it was not being accessed, the CPU ran at full speed even when the system was doing light work, and the LCD panel continued to display even when the user walked away from the screen.

Windows has a thing called power management. Which is just the cooperation of the hardware, the BIOS, and the OS to reduce power.

System Management Mode
Intel began the process of power management with a series of new features built into the 386SX CPU. These new features enabled the CPU to slow down or stop its clock without erasing the register information, as well as enabling power saving in peripherals. These features were collectively called System Management Mode (SMM). All modern CPUs have SMM. To take advantage of SMM, the system needed a specialized BIOS and OS to go with the SMM CPU. To this end, Intel put forward the Advanced Power Management (APM) specification in 1992 and the Advanced Configuration and Power Interface (ACPI) standard in 1996.
Requirements for APM/ACPI
To function fully, APM and ACPI require a number of items. First, they require an SMM-capable CPU (All modern CPUs are SMM capable). Second they need an APM-compliant BIOS that enables the CPU to shut off the peripherals when desired. The third requirement is devices that will accept being shut off. These devices are usually called Energy Star devices. To be an Energy Star device, a peripheral must be able to shut down without actually turning off and show that it used less power than the non-Energy Star equivalent. Last, the system’s OS must know how to request that a particular device be shut down, and the CPU’s clock must be slowed down or stopped.

ACPI goes beyond the APM standard by supplying support for hot-swappable devices, always a huge problem with APM.

APM Levels
APM defined four power-usage operating levels for a system. These levels are intentionally fuzzy to give manufacturers considerable leeway in their use; the only real difference among them is the amount of time each takes to return to normal usage. These levels are as follows:

-Full On: Everything in the system is running at full power. There is no power management

-APM Enabled: CPU and RAM are running at full power. Power management is enabled. An unused device may or may not be shut down.

-APM Standby: CPU is stopped. RAM still stores all programs. All peripherals are shut down, although configuration options are still stored. In other words, you won’t have to reinitialize the devices to get back to APM Enabled.

-APM Suspend: Everything in the system is shut down or at its lowest power consumption setting. Many systems use a type of Suspend called hibernation, where critical information is written to the hard drive. Upon a wake-up event, the system is reinitialized, and the data is read from the drive to return the system to the APM Enabled mode.

ACPI Levels
ACPI, the successor to APM, handles all these level plus a few more, such as “soft power on/off”, which enables you to define the function of the power button. ACPI global (G) and sleeping (S)

-G0 (S0): Working state

-G1: Sleeping state mode. Further divided into four S states.

S1: CPU stops processing. Power to CPU and memory (RAM) is maintained.

S2: CPU is powered down.

S3: Sleep or Standby mode. Power to RAM still on.

S4: Hibernation mode. Information in RAM is stored to nonvolatile memory or drive and powered off.

-G2 (S5): Soft power off mode. Certain devices used to wake a system, such as keyboard, LAN, USB, and other devices, remain on, while most other components are powered to a mechanical off state (G3).

-G3: Mechanical off mode. The system and all components, with the exception of the real-time clock (RTC), are completely turned off.

Configuration of APM/ACPI
You configure APM/ACPI via CMOS settings through your operation system. OS settings override CMOS settings.

First is the ability to initialize power management; this enables the system to enter the APM Enabled mode. Often CMOS then presents time frames for entering Standby and Suspend modes, as well as settings to determine which events take place in each of these modes.

Many CMOS versions present settings to determine wake-up events, such as directing the system to monitor a modem or a NIC. You’ll see this feature as Wake on LAN, or something similar. A true ACPI-compliant CMOS provides an ACPI setup option.

In Windows, APM/ACPI settings can be found in the Control Panel applet Power Options. Windows offer power plans that enable better control over power use by customizing a Balanced, High performance, or Power saver power plan. Another feature, Hibernate mode, takes everything in active memory and stores it on the hard drive just before the system powers down. When the system comes out of hibernation, Windows reloads all the files and applications into RAM.

Manual Control over Power Use
Most portables give you several manual options for reducing battery use in certain circumstances. Many newer portables (not to mention Windows 8 and later) also borrow a feature from smart phones and tablets for disabling most or all their wireless components at once: airplane mode. Airplane mode is also a great way to disable power-sucking components.

One of the best ways to conserve battery use is to plan ahead of times when you will be unplugged. This can mean a lot of different things in practice, but they all boil down to thinking of to minimize the number of programs and hardware devices/radios you will need to use while your laptop i running on battery power.

Better than that, Windows enables me to designate the files and folders I need as offline files, storing a local, duplicate copy of the files and folders on my hard drive.

To designate a folder and its contents as offline files, right-click on the folder you want and select Always available offline from the menu. The sync will occur and you are done. When you want to open the files offline, go to the Control Panel and open the Sync Center applet. Click the Manage offline files link in the Tasks list to open the Offline Files dialog box. Click the View your offline files button and you are in.

Cleaning
To clean your portable computer you can blow it out with compressed air. To clean the screen use the appropriate screen cleaner to remove fingerprints and dust from the fragile LCD panel.
Heat
To manage and maintain a healthy portable computer, you need to deal with heat issue. Every portable has a stack of electronic components crammed into a very small space. Unlike their desktop brethren, portables don’t have lots of freely moving air space that enables fans to cool everything down. Even with lots of low-power-consumption devices inside, portable computers crank out a good deal of heat. Excessive heat can cause system lockups and hardware failures, so you should handle the issue wisely.
Tripping
Pay attention to where you run the power cord when you plug in a laptop. One of the primary causes of laptop destruction is people tripping over the power cord and knocking the laptop off of a desk.
Storage
If you aren’t going to use your portable for a while, storing it safely will go a long way toward keeping it operable when you do power it up again. Investing in a quality case is worth the extra few dollars, preferably one with ample padding. Not only will this protect your system on a daily basis when transporting it from home to office, but it will keep dust and pet hair away as well. Also, protect from battery leakage, at least on devices with removable batteries, by removing the battery if you plan to store the device for an extended time.
Travel
If you travel with a laptop, guard against theft. If possible, use a case that doesn’t look like a computer case. A well-padded backpack makes a great travel bag for a laptop and appears less tempting to would-be thieves, though some brands and styles of these are still quite obvious. Before you leave, make sure to backup any data on your hard drive.

Make sure to have at least a little battery power available. When you are at a airport you might have to power on your laptop to show security it is in fact a laptop.

If you travel to a foreign country, be very careful about the electricity. North America uses about 115 Volts AC, but most of the world uses 230 Volts AC. Many portable computers have auto-switching power supplies, meaning they detect voltage at the outlet and adjust accordingly. For these portables, a simple plug converter will do the trick. Other portables computers, however, have fixed input power supplies, which means they run only on 115 Volts AC or on 230 Volts AC. For these portables, you need a full blown electricity converting device, either a step down or step up transformer.

Shipping
Much of the storage and travel advice can be applied to shipping. If possible, remove batteries and optical discs from their drives. Pack the portable well and disguise the container as best you can. Back up any data and verify the warranty coverage.
Security
There are multiple ways to prevent or deter people from stealing your stuff. You can use a laptop lock to lock down your laptop on a surface. There are also many GPS tracking services, such as LoJack, to track down your stolen laptop.
Upgrading and Repairing Laptop Computers
When taking apart a portable computer you need to watch for ESD and be careful. Try to get an instruction guide for the disassembly as portable computers are harder to take apart.
Disassembly process
First things first, you want to power off the system, unplug it from the wall, and drain the battery. After that take the battery out (check manufacturer’s guide for battery and how to take it out).

Once you do that you need to document where all of the screws on the laptop goes. Laptop screws are very small and usually not standard so if you lose a screw finding a replacement will be tough.

When taking parts out of the laptop, organize them and mark where they go.

Laptops are tricky things to deal with and sometimes you will have to redirect the customer to a dedicated laptop repair person. If you feel like not doing that, there are many third party sources to look up and see how to do different things, like removing a keyboard. YouTube and iFixit are great places to start.

Watch the video/tutorial and if you feel it is too difficult for you or if you do not have the right tools, find a dedicated tech to do the job.

Upgrading RAM
Stock factory portable computers almost always come with minimal amount of RAM, so one of the first laptop upgrades will be to upgrade RAM. For laptops you will be using SO-DIMM RAM.

The amount of RAM you will need depends on what applications you are running. If you have a client who is just on Facebook then you will only need 2-4GB. If you user plays a graphic intensive video game then 8GB+ will be good.

How to Add or Replace RAM
See video on Internet.
Shared Memory
Some laptops (and desktops) support shared memory. Shared memory reduces the cost of video cards reducing the amount on the video card itself. The video card uses regular system RAM to make up for the loss.

The obvious benefit of shared memory is a less expensive video card with performance comparable to its mega-memory alternative. The downside is that your overall system performance will suffer because a portion of system RAM is no longer available to programs.

Some systems let you control the shared memory while others just allow you to turn it on/off in the CMOS.

Upgrading Mass Storage
You can replace a hard disk drive (HDD), solid-state drive (SSD), or solid-state hybrid drive (SSHD) in a portable PC fairly easily, especially if the laptop is only a few years old. SATA drives in the 2.5 inch format are a standard in laptops.

If you have an ancient laptop it will likely have a PATA drive, so you need to pay attention to the jumpers and cabling.

One of the best upgrades is going from an HDD to an SSD. SSDs are way faster than HDDs and use less electricity. The only con about SSDs are their price but you can find a 500-GB SSD for under $200.

Hardware Replacement
Once go beyond upgrading RAM and repairing a hard drive on a portable, you take the plunge into the laptop-repair specialty. You can replace some components by lifting them out, detaching a ribbon cable, and then reversing the steps with the replacement part. Other parts require a full teardown of the laptop to the bare bones, replacement part. Because every portable differs, you need to look at the manufacturer’s manual.
Components
Replaceable components require more work than the RAM or drive upgrades, but replacing them generally falls into the category of “doable”. What I call components are the battery, keyboard, optical drive, internal speaker(s), and plastic parts.
Battery
If a battery’s performance falls below an acceptable level, you can replace it with a battery from the manufacturer or from an aftermarket vendor. Although this swap should be a simple swap replacement, you might encounter a situation where the real problem wasn’t the battery per se, but an inadequate of malfunctioning charging system.
Keyboard
Getting a keyboard off laptop computer often requires little pry bars, but also look for screws, clips, and so on. Keyboards connect via tiny, short, and very delicate cable, often held down by tape. Replacing one is tricky.
Optical Drive
Replacing an optical drive can present a challenge. If the drive is part of a modular system, just pop out the old drive and pop in a new one. If the drive is part of the internal chassis of the portable on the other hand, you are looking at a full dissection.
Speaker
Replacing the internal speaker or speakers on a laptop can be simple or a total pain, depending on where the speakers connect. Some laptops have speakers mounted on the outside of the chassis. You pry off the covers, pull out the little speakers, disconnect the cable, and then reverse the process for replacement speakers.
Frame
All of the sophisticated electrified components that make our portables work are held together by a variety of plastic, metal, and rubber parts. Over time, these parts wear and might need to be replaced.

To replace these parts, you will need the device model and you may also need to hunt down the part number using manufacturer or third-party resources.

Expansion Cards
Not to be confused with ExpressCards, many portables have one or more true expansion slots for add-on cards. The more modular varieties will have a hatch on the bottom of the case that opens like the RAM hatch that gives you access to the slot(s). This enables you to change out an 802.11n wireless card, for example, for an 802.11ac card, thus greatly enhancing the Wi-Fi experience on this device.

Another consideration with expansion cards applies specifically to wireless. Not only will you need to connect the card to the slot properly, but you must reattach the antenna connection and often a separate power cable.

You will fine one of two types of expansion slot in a portable: Mini-PCIe and M.2. The older ones (2013 and earlier) use PCIe and the newer devices are adopting M.2.

CPU
Replacing a CPU on a modern portable takes a lot more work than replacing RAM or a Mini-PCIe expansion card, but follows the same general steps.Many CPUs mount facing the bottom of the portable, so that the venting goes away from your hands.

First, remove all power from the laptop, including the battery if possible. Remove the hatch to expose the CPU. Remove the heat sink and fan assembly and lift out the CPU. Replace it with another CPU, apply thermal paste, and reattach the heat-sink and fan assembly. Reconnect the power connector and you are good. Besides a few screws, there is really no difference in a mobile CPU and a desktop CPU.

Integral Parts
Some hardware replacements require you to get serious with the laptop, opening it fully to the outside, removing many delicate parts, and even stripping it down to the bare chassis.

Portables open in two different ways, depending on the manufacturer. You either peel away layers from the top down, through the keyboard, or from the bottom up, through the base. Either direction requires careful attention to detail, part connectivity, and locations. Every one of the replacements requires you to detach the screen from the main chassis of the portable. Aside from finding the connection points and removing the proper screws, you need to pay attention to the connection points for the data stream to the monitor and the antenna that is in the frame of the display. Once you have it stripped down, you replace whichever component you are there to replace and then begin the process of building it back up.

Laptop Won’t Power On
-Verify AC power by plugging another electronic device into the wall outlet. If the other device receives power the outlet is good. You can also test the outlet with a multimeter.

-If the outlet is good, connect the laptop to the wall outlet and try to power on. If no LEDs light up, you may have a bad AC adapter. Swap it with a known good power adapter.

-A faulty peripheral device might keep the laptop from powering up. Remove any peripherals such as USB, FireWire, or Thunderbolt devices.

Poor Performance
-The most common reason for slow performance is running applications and processes consuming high resources. All OS have a way to check this, such as Task Manager in Windows or Activity Monitor in Mac OS X, and look into problems with any you find. They may need to be closed or stopped, you may need to reboot, or the application may need an update.

-Extreme performance issues may lead to a frozen system. If they don’t resolve on their own and you can’t interact with the device, you may need to perform a hard reboot.

Battery Issues
-A swollen battery will probably go unnoticed at first, and the symptoms it creates may be hard to identify if you are not aware it can happen. the cause is usually over charging, perhaps due to a failure in the circuit that should prevent it, but the early systems might be a laptop doesn’t sit right on flat surfaces, a screen doesn’t fit flush when closed, problems with input devices like the touchpad or keyboard, and trouble removing or inserting a removable battery.

-If you have a laptop with a battery that won’t charge up, it could be one of two things: the battery might be cooled or the AC adapter isn’t doing its job. To troubleshoot, replace the battery with a known-good battery. Alternatively, remove the battery and run the laptop on AC only. If that works you know the AC adapter is good. If it does’t replace the AC adapter.

-The reason for very short battery life in a battery that charges properly are fairly benign. The battery has usually outlived its useful life and needs to be replaced, or some programs or hardware are drawing much more power than usual.

Overheating
-If your device is overheating, blow it out with compressed air and make sure the power connectors for the fans are plugged in.

-Make sure you have a cool environment

Display Problems
-If the laptop is booting (you hear beeps and the drives) but the screen doesn’t come on properly, first make sure the display is turned on. Press the FN key and the key to activate the screen a number of times until the laptop display comes on. If that doesn’t work, check the LCD cutoff switch and make sure it isn’t stuck in the down position.

-If the laptop display is very dim it must have lost an inverter. the clue here is that inverters never go quietly. They can make a nasty hum as they are about to die and a popping noise when they actually fail.

-If there is a big crack on the screen, laptops have a port for plugging in an external monitor.

-If you plug a laptop into an external monitor and that monitor does not display, remember that you have both a hardware and as OS component to making dual displays successful. There is usually a combination of FN and another key to toggle among only portable, only external, and both displays.

-Many manufacturers have switched to LED displays on laptops, which has led to a phenomenon many techs long behind us: flickering displays. LED displays do not work the same as CCFL backlights.

-There are two things you can do with a flickering LED display: crank up the brightness so that it goes away (and thus reduce battery life) or replace the laptop.

-If the screen orientation on a Windows portable doesn’t change when the device is rotated, auto-rotation may be disabled. Likewise, if the orientation changes at the wrong time, you can lock rotation via the Screen option in the Settings charm, or via the Display applet in the Control Panel.

Wireless Devices (Bluetooth, Wi-Fi, Mobile Broadband, NFC, or GPS) Don’t Work or Work Intermittently
-If the wireless doesn’t work at all, check along the front, rear, or side edges of the laptop for physical switches that toggles the internal wireless adapter, Bluetooth adapter, or airplane mode on and off.

-If a tech has recently replaced a component that required removal of the laptop display, dead wireless could mean simply a disconnected antenna. Most portables have the antenna built into the display panel, so check the connection

-Try the special key combination for your laptop to toggle the wireless or Bluetooth adapter, or one for toggling airplane mode. You usually press the FN key in combination with another key.

-You might simply be out of range or, if the wireless works intermittently, right at the edge of the range. Physically walk the laptop over to the wireless router or access point to ensure there are no out-of-range issues.

-With Bluetooth specifically, remember that the pairing process takes action or configuration on both devices to succeed. turn on the Bluetooth device, actively seek it, and try again.

-If only the GPS is not functioning, privacy options may be preventing applications from accessing your GPS location information. Check and make sure GPS is enabled.

-If only the NFC is not functioning, you may need to enable a setting to allow communication with nearby devices. In Windows, open the Proximity applet in the Control Panel and make sure Proximity support is enabled.

Audio Problems
-If audio isn’t working when it should be, check for a hardware mute or volume button or switch and verify through the notification area Volume icon that the audio output isn’t muted.

-If the device has had repairs or upgrades lately, make sure the speakers are properly connected.

-If no sound is coming from the device speakers, try plugging in a pair of headphones or some external speakers. If these work fine, there is a chance the built-in speakers have been damaged.

-If headphone work fine with the device, the speakers may need replacing. first, make sure the device has been rebooted, double check the audio output device settings, try changing and resetting the default output device, and try disabling and re-enabling the appropriate device.

Input Problems
-Before assuming an input problem is hardware related, confirm that the system is otherwise running smoothly. Input devices may appear not to work or work erratically if the system is freezing up.

-If none of the keys work on your laptop, there is a good chance you unseated the keyboard connector.

-If you are getting number when you are expecting to get letters, the number lock (NUMLOCK) function key is turned on. Turn it off.

-Laptop keyboards take far more abuse than the typical desktop keyboard because of eating or drinking around it. If you have a laptop with sticking keys, look for debris in the keys. Used compressed air to clean it out.

-A laptop keyboard key that doesn’t register presses or feels sticky may also have had a switch knocked out of place, especially if the key appears slightly raised or tilted. Look for steps on reattaching/detaching the if possible.

-If the touchpad is having problems, shooting compressed air into it can get some of the debris out of that area.

-If the touchpad is unresponsive or erratic, a good first step is checking the screen for dirt, grease, or liquids, which can make the system go haywire; wipe it down with a dry microfiber cloth.

-Some touch screens may appear to work improperly if they are registering an unintentional touch. Depending on the design of the device, it may be tempting to hold it in a way that leaves some part of your hand or arm to close to the edge of the screen; some devices will register this as a touch.

-Your device may have touchscreen diagnostics available through hardware troubleshooting menus accessible through the BIOS. Refer to the manufacturer’s resources for how to access these diagnostics. If available, they are a quick way to identify whether you are looking at a hardware or software/configuration issue. Try recalibrating the touch pad.