This chapter provides a study guide for CompTIA A+ Exams 220–602, 220–603, and 220–604. Various sections in this chapter are organized to cover the related objectives of the exam. Each section identifies the exam objective, provides an overview of the objective, and then discusses the key details that you should grasp before taking the exam.
Note that the Exam 220–602 includes all sections given in this chapter. Some sections are omitted in Exams 220–603 and 220–604 and have been noted at appropriate places in the chapter. An overview of the sections in this chapter is provided in the following paragraphs:
This section covers the basic steps involved in installing, configuring, upgrading, and troubleshooting personal computer components, such as processor, memory, and storage devices, including hard disks, removable drives, display devices, and input/output devices. Preventive maintenance of these components is also covered in this section.
This section covers a discussion of communication technologies used for laptops and mobile devices; installation and optimization of laptop specific hardware; and basic diagnostic procedures to troubleshoot and resolve problems. This section is not covered in Exam 220–603.
This section discusses configuring various components of the operating system, performance optimization, troubleshooting tools and techniques, and preventive maintenance procedures. This section is not covered in Exam 220–604.
This section covers the basics of printing and scanning processes, optimizing performance, troubleshooting techniques, and preventive maintenance of printers and scanners.
This section covers the fundamentals of computer networking, installation, troubleshooting techniques, and preventive maintenance procedures. This section is not covered in Exam 220–604.
This section discusses the basic concepts of computer security, including access control methods, configuration of software, data security, and troubleshooting. Also covered in this section are preventive maintenance measures for maintaining a secure working environment.
The objectives for A+ Exams 220–602, 220–603, and 220–604 also include "Safety and Environmental Issues" and "Communications and Professionalism" topics. Refer back to Chapter 2 for a review of these topics. Also note that "Safety and Environmental Issues" is not covered in Exam 220–603, and "Communications and Professionalism" is not covered in Exam 220–604.
In order to complete study for these A+ exams, we recommend that you get access to a computer that can be opened and, if required, its parts can be inspected, uninstalled, reinstalled, or upgraded whenever necessary. The personal computer should preferably have the following hardware configurations:
An Intel 233 MHz or faster processor (350 MHz recommended) with a CD-ROM or DVD drive
A minimum of 256 MB RAM (512 MB recommended)
A least 2 GB of free hard disk space
A Super VGA or higher-resolution monitor
A keyboard and a mouse
You must also have access to a printer with appropriate driver software and, if possible, a scanner. Besides this, you will need appropriate tools in order to install, uninstall, or upgrade the components of the personal computer.
The exercises included in this Study Guide should be part of your preparation for the exam. Do not perform any exercises in a production environment and do not use any PC that you use for your regular work. Instead, create a test environment with the recommended hardware.
This part of the A+ exam deals mainly with installing, upgrading, and basic troubleshooting of different parts of personal computers. As a hardware technician, you are expected to have good knowledge of installation and upgrading procedures for different components of personal computers, including storage devices, motherboards, processors, memory, power supplies, adapter cards, ports, and cable types used both inside the computer and for connecting external peripherals. This section provides an overview of installation, optimization, troubleshooting, and preventive maintenance procedures for these components.
Chapter 2 includes a detailed discussion of various components of personal computers, their identification, characteristics, and basic installation and troubleshooting procedures. I encourage you to review the fundamentals one more time before you take Exams 220–602, 220–603, or 220–604.
Every component inside and outside a computer needs to be installed or upgraded using certain standard procedures. Most of these procedures come in the form of instructions from the vendor. In some situations, when no predefined procedure or instructions are available, you might have to use your common sense, knowledge, skills, and experience to complete the given task. The installation and upgrade process starts right from selecting an appropriate component, installing it, and testing it to verify that it works as expected. This section provides a discussion of some basic procedures to install, remove, and upgrade computer components.
Hard disks, floppy disks, CD-ReWritable (CD-RW), and DVDs are all categorized as storage devices in computers. Among these, the hard disks remain the primary means of data storage. The normal size of a hard disk drive is 3.5 inches (as opposed to 5.25 inches for CD and DVD drives). When installing additional drives, you might require appropriate screws to fix the drive into the cage. It is a good idea to test the screws for their size before installing a drive in the drive cage. In this section, we will look at adding, removing, and upgrading procedures for these devices.
Storage devices are available in various makes, models, types, and capacities. You need to have a good understanding of your requirements. When installing or upgrading a storage device, you must make sure the following is true:
The device fulfills your storage requirements.
The device is compatible with the existing computer hardware.
The computer Basic Input Output System (BIOS) supports the type of device you are going to install.
The operating system can recognize the device and use its full storage capacity.
There are provisions in the existing system for adding another device.
When you have selected a drive and its specification, check the return or refund policy of the vendor.
Shop around a little to get the best price and after-sales support.
As a simple example, if you are running out of hard disk storage and want to add another drive, you must make sure that there is enough room inside the computer case for installing another drive. Some computers are already full of CDs, DVDs, and multiple hard drives and do not have room for additional devices. For CD and DVD ROM drives, you need to verify the speed of the drive. CD-Recordable (CD-R) and CD-RW drives have different speeds for reading and writing the disk. Check your requirements before you select a drive. In the case of DVD writers, make sure that the drive supports the format you are already using or intend to use. Most new drives support multiple formats such as DVD-R or DVD+R.
Installing hard disk drives requires special attention. Make sure that the drive is kept in its protective cover until you are ready to install it. When you take out the drive from the cover, avoid touching the bare areas of the drives where its circuit board or small semiconductor parts are located. The following steps should be followed when installing a hard disk:
Set the jumpers on the hard disk to configure it for Cable Select, Master, or Slave (in case of multiple drives). If you put the jumper on Cable Select, the motherboard will view the drive as primary or secondary. Be careful about the orientation of the jumpers. Jumper configuration is usually printed on top of the drive. Setting the jumpers incorrectly is a common mistake when installing hard disks.
Select the primary or secondary hard drive cable (IDE cable) and appropriate connector. Most IDE cables have two connectors, while some of them have only a single connector. In the case of Cable Select, you can connect the hard drive to any of the connectors. The extra connector is used to install another hard drive or a CD/DVD drive.
In case you are replacing the drive, carefully remove the installed drive by first removing the connectors and then its screws. Make sure that you do not force the screw. In some computer cases, you might have to remove the drive cage itself that holds all drives.
Insert the new drive carefully in the drive cage and connect the IDE cable connector. Tighten the screws and connect the power connector. The power connector has polarity that ensures that you will not connect it in the wrong direction.
Reinstall the drive cage if you removed it to install the hard disk.
New hard disks must be formatted before you can use them. You can run the Disk Management snap-in on a Windows XP or Windows 2000 computer to partition and format the disk and assign drive letter(s) and volume label(s). You can also run the format.exe command from the command prompt to format the disk. The DISKPART utility in Windows XP can be used for all disk related tasks except formatting the disk.
Some computer cases do not require screws for CD and DVD drives. The drive is simply pushed, and it snaps-in and secures in its place inside the drive cage. In some other cases, the drive must be inserted and then the screws need to be tightened. The following steps should be followed when installing a CD or DVD drive in case it needs to be tightened using screws:
Remove the plastic slot cover from the computer case.
Set the appropriate jumpers on the drive to configure it as a slave drive. In most cases, the CD or DVD drive is configured as a slave drive.
Select the appropriate IDE cable to connect it to the primary or secondary port.
Insert the drive and tighten the screws. Make sure that you do not use force while using the screwdriver.
Connect the IDE cable carefully with the correct orientation and polarity.
Connect the audio cable, if available.
Connect the power cable.
Reinstall the drive cage, in case you removed it before installing the drive.
The screws used for floppy drives are different from the ones used for hard drives and CD and DVD drives. Floppy drives use small screws with fine threads. Make sure that you have the correct size of screws available. Test one or two screws before installing the drive into the cage. Follow the steps below when installing a floppy disk drive:
Insert the floppy drive into the drive cage at an appropriate location.
Tighten the screws gently. Do not use force.
Locate and connect the cable with the correct orientation. If this is an additional floppy drive (Drive B:), use the correct connector from the cable.
Connect the power cable.
Reinstall the drive cage, in case you removed it before installing the drive.
Motherboards may need to be taken out and reinstalled in computers for the purpose of troubleshooting or when they need to be replaced with new ones. When you are required to replace a motherboard, you must be careful when selecting an appropriate motherboard. The following are some guidelines for selecting motherboards:
Define your requirements clearly and make sure your selection meets or surpasses these requirements.
Do your homework regarding selection of a make, model, and vendor.
Check the technical details of the board, such as the chipset used, the speed of the system bus, and the type of memory modules (RAM). The system bus speed determines how fast the data is transferred to different parts of the computer.
Check the amount of onboard memory and the maximum supported memory, and whether there is a provision to add memory when required.
Check what components are built onboard and what features will require add-on cards. For example, many motherboards have built-in dial-up modem and network adapters.
Check how many expansion slots are available for add-on cards (adapters).
Check what different kinds of I/O ports are available on board. Also check the number of ports. For example, most new motherboards have built-in firewire and several USB ports.
If the computer is to be used for graphics applications, check the amount of video RAM available on the motherboard.
There may be other special requirements depending on how the computer is to be used. Make sure that you ask for and understand the vendor's support and return and refund policies.
Complete the following steps to remove and/or install a motherboard in the computer case. But first, make sure that you are wearing an antistatic wrist strap, and that you keep the new motherboard in its protective cover (called the antistatic bag) until you are ready to install it.
Open the case covers carefully. The correct procedure depends on the type of case you have on the computer.
Remove the IDE and power cable connectors from the hard disk and CD/DVD drives as well as all the connectors from the floppy disk drives.
Check whether you will need to remove the drive cage in order to remove the existing motherboard and install a new one. Put all the screws in a safe place.
Carefully remove the front cover and then the drive cage (by removing any required screws).
Examine the back panel of the computer case to determine which screws need to be removed.
Remove the main screws that hold the motherboard to the case. You might have to remove the I/O shield as well.
Remove the old motherboard carefully and put it aside.
Hold aside all the power cables and the cables from parts such as speakers so that the area is clear of any hindrances.
Take out the new motherboard from its protective cover. Place the motherboard inside the case and see whether it fits well in its place. Hold the motherboard only from its sides and do not touch any components to avoid damage by static discharge from your body. Make sure that the screws can be fixed at appropriate locations (called standoffs). You might have to move some standoffs to appropriate places, as required by the new motherboard.
Secure the motherboard to the case using proper screws. This completes the physical installation.
Connect the power cable, the speaker cable, the reset switch cable, the hard disk LED, and other LED cables, depending on the type of motherboard and the computer case. Consult the motherboard manual for specific instructions.
Reconnect all cables at appropriate places.
Reinstall the drive cage in case you removed it earlier.
Test the motherboard by connecting the monitor, the keyboard, the mouse and other devices as appropriate.
When the testing is done and everything works perfectly, reinstall the case covers as required.
After you have installed the motherboard, test it by installing the minimum number of components required to boot the system. Once you are sure that the motherboard is working fine, install all other components, one by one, and repeat the testing. This way you can easily detect whether any of the add-on components are not compatible with the new motherboard.
If you are assembling a new computer, you will find that the power supply unit comes preinstalled with the case. Most vendors of computer cases deliver power supplies with the case. If you are replacing a defective power supply, the procedure is very simple. Before you purchase a power supply unit, consider the following:
Make sure that you select a power supply with correct voltage and current ratings.
Different motherboard chipsets require different types of power supplies. Make sure that you obtain the correct type of power supply unit.
Ensure that the power supply will fit into the computer case.
Check with the vendor about the return or refund policy.
The following is a general procedure to replace and install a power supply unit:
Turn off the computer and remove the power cord from the wall socket as well as from the rear panel of the computer.
Open the computer case and put it aside. If the computer was on for long hours, let it cool down for about 15 minutes.
Remove the power supply connectors from the motherboard and disk drives.
Remove the front panel and disconnect the two mains cables from the power switch.
Remove the screws that hold the power supply from the rear panel of the computer.
Determine whether you will need to remove additional components to safely remove the power supply unit from the case.
Remove the power supply unit gently so that it does not hit any internal parts of the computer.
Place the new power supply in the computer case and tighten the screws on the rear panel.
Connect all connectors back one by one. Do not use force.
Replace the front panel of the computer after connecting the power switch.
Reconnect the power cable. Turn on the computer to test that the new power supply unit is functioning as expected.
When the testing is done, replace the computer case.
Installing a CPU requires that you always wear the antistatic wrist strap. Do not remove the new CPU from its protective cover until you are ready to insert it in the CPU socket on the motherboard. The following steps explain the general procedure for installing or replacing a CPU:
Open the computer case and examine the existing CPU and type of socket. Check the type of CPU socket and whether you will need any special tools to remove the CPU from the socket.
Some CPUs come preinstalled with a heat sink and a cooling fan. On some other CPUs, you must use the old heat sink and fan. Examine how these can be removed safely and reinstalled on the new CPU.
Most CPU sockets have a lever on one side that frees the CPU from the socket.
Pull the CPU socket lever (also called the Zero Insertion Force lever) gently to loosen the CPU from the socket. Remove the CPU carefully and put it aside in a protective cover.
Examine the small pinholes on the socket. You will notice that the CPU cannot be inserted with the wrong orientation.
Take out the new CPU from its cover. Examine it and hold it only from its edges in the correct direction. Place the CPU in the socket with the correct orientation.
Push the socket lever down gently to secure the CPU in the socket.
If you need to install the heat sink and the cooling fan, you will need a thermal conductive compound or tape that sits between the CPU and the heat sink. This compound or tape ensures the flow of heat from the CPU surface to the heat sink. Place a drop or two of the compound on the CPU surface or place the thermal tape on the bottom of the heat sink, as required. Follow the instructions that come with the CPU package.
Place the heat sink and the fan assembly on top of the CPU and secure it in its place by locking the steel clips or other mechanism as required.
Connect the cooling fan wires to the appropriate connector on the motherboard.
You can test the installation by simply turning on the computer. The initial BIOS test displays the speed of the processor. This test will indicate whether there is any problem with the installation. When you are done, reinstall the cover of the computer case.
You can test a new power supply even before you install it in the computer case. If you know different voltages on connector pins, turn on the power supply, take a multimeter, and measure all DC voltages on all connector pins one by one. You can also use a power supply tester for this purpose. You will need to short circuit the main cables that are connected to the power switch by using a simple wire. Be careful and do this before you plug in the main cable to the wall socket.
There are a few important things that you must make sure of before purchasing a new memory module. These are as follows:
There is a provision for expanding memory on the motherboard. This means that free slots (also called memory banks) are available. If not, you might have to replace the old memory modules with new ones (as opposed to simply adding more RAM).
If you are adding memory modules in free slots, make sure that the new modules are compatible with the existing ones. Incompatible modules will either not work at all or will create intermittent system problems.
If you need to buy new memory modules, check the motherboard manual to see what type of memory it supports and the maximum amount of installable memory.
Consult the motherboard manual to verify that the system bus will support the memory module you are buying or installing.
Make sure that you are wearing a properly grounded antistatic wrist strap all the time. Static charge from your body can immediately damage the memory module. Hold the module only from its edges.
The following is a general procedure for adding or removing memory modules:
Keep the memory sticks in their protective antistatic covers until you are ready to install them.
Always wear grounded antistatic wrist straps.
Remove the old memory sticks carefully by releasing the side levers.
Hold the new memory stick in the correct orientation, align it to the socket, and push it down firmly using your two thumbs.
Push the levers back into place.
You can test the new memory module or expanded memory capacity by turning on the computer. The BIOS test on system startup will indicate the amount of memory you have on the system. If the total amount of memory does not match the expected capacity, there may be some problem with the memory module or with your installation.
Adding or removing a display device or a monitor is a simple process. You must select an appropriate monitor to suit your requirements. Verify that the new monitor supports the number of colors and the resolution you need. For graphics applications, you might require a monitor with 1280 × 1024 pixels or better resolution with high 32-bit color depth. Moreover, you might have to look for an LCD monitor if space is limited.
To replace an old monitor, power off the monitor and remove the power cord from the wall socket. Remove the cord that connects the monitor to the computer. Place the new monitor and make the necessary connections. If no driver needs to be installed, the monitor is ready to use when you turn on power.
Monitors are usually automatically detected, and the operating system will install the necessary drivers for them. For most applications, you can configure the monitor colors and screen resolution from the Display properties window. Right-click an empty area on the desktop and click Properties. Click the Settings tab to configure the color depth and screen resolution. For some graphics applications such as Photoshop, you may need to configure the monitor properties appropriately to set the display. This is known as adjusting the monitor gamma.
The procedure for adding or removing an input device depends on the type of device you are installing. Simple input devices such as the keyboard and mouse are easy to remove and install. On some older computers, the mouse is installed on the serial port and a driver is installed for the operating system to recognize it. Most newer computers use the PS/2 ports or the USB ports for both devices, and the Plug and Play (PnP) feature automatically detects them and the operating system automatically installs appropriate drivers.
The installation of an adapter card depends on the card's type and purpose. Most of the cards are installed on one of the available expansion slots on the motherboard. When you are replacing an old adapter or buying a new one for the computer, verify the following things:
Check the type of expansion slots available in the computer. In new computers, all expansion slots are the PCI type, while some old computers have ISA or EISA slots. Some computers have a mix of ISA and PCI slots. If you are working on an old computer, make sure that the system bus will support the type of adapter you are going to buy or install in the computer.
Check that the adapter driver is supported by the operating system. Go for an adapter that has been tested by Windows Hardware Quality Labs (WHQL). WHQL tests and verifies the functionality of the adapters and other devices. Insist on signed device drivers.
Check with the vendor whether an upgraded device driver is available. The driver might have been upgraded after the adapter was manufactured and shipped to the retailer.
Check whether the new adapter is PnP-compatible. PnP adapters are automatically detected by computer BIOS and the operating system.
The following is a general procedure for replacing or installing an adapter card:
Remove the computer case by removing the screws.
Find an empty expansion slot. Use a slot that is easily accessible so that you can insert the card without disturbing other installed adapters.
Remove the slot cover from the computer case using long nose pliers.
Insert the adapter in the selected expansion slot and push it gently so that it sits well in the slot. Tighten the screw, if required.
Turn on the computer to see whether the BIOS and operating system recognize the adapter. If the adapter is not PnP-compatible or the system BIOS does not support PnP, you might have to test the adapter by installing its device driver.
When the testing is done and the adapter works as expected, you may close the computer cover.
Troubleshooting personal computers requires special skills that you learn by experience. The more experience you have, the more quickly you will be able to identify the cause of the problem and apply a correct solution. This section deals with some very general and basic troubleshooting tools and techniques that will help you build a basic understanding of the computer troubleshooting process.
Basic troubleshooting procedures include gathering information about the problem from the user, looking at problem symptoms, and determining the most probable cause. Then you can isolate the problem and determine an appropriate solution to rectify the problem.
Visual inspection of problem symptoms is very helpful in starting the troubleshooting process. For example, if some user has reported a network connectivity problem, you can verify that the network cable is securely connected to the computer, that the connector is attached properly, and that the LED indicators are showing normal operation.
Similarly, if the problem is with an internal component of a computer, you can open the computer case and make a visual inspection to make sure that the adapters and memory modules are seated well in their respective slots. In case a drive is not functioning, check whether the power cable or the data cable is disconnected or loosely connected.
Audible inspection refers to beep codes generated by the computer BIOS when the computer is powered on. The Power-On Self-Test (POST) is run on system startup to determine that the system is functioning properly. It detects various components installed in the system. Since this test is run during system startup and the BIOS does not yet have access to the video card or the monitor, it produces audible signals or beeps to report any error messages. The pattern of beeps usually indicates the type of problem.
To exactly understand the meaning of a beep pattern, you might need to refer to the motherboard manual or the documentation of the BIOS manufacturer. American Megatrends Incorporated (AMI), Award, and Phoenix are the three main vendors of computer BIOS programs.
You will need to know the correct BIOS make and its version number to determine the meaning of beep patterns. A missing beep usually indicates a problem with the motherboard. Beep codes can be a long beep, a short beep or a combination of long and short beeps to make a specific pattern, indicating a problem with a certain part of the motherboard. If the beep pattern indicates normal system startup and there is no display, make sure that the monitor is properly connected. You can also replace the monitor to verify that the problem is not with the monitor.
Removing add-on components from the computer and starting it with a minimal configuration can help trace several problems. For example, you can remove the network adapter, the modem card, or an extended graphics card one by one and restart the computer to see whether the computer starts working again.
On the software side, Windows XP and Windows 2000 Professional include advanced boot options to help determine problems with system components. You can use Safe Mode to start the system with minimum configuration. If this works well, you can use Safe Mode with Networking to add the networking components. Safe Mode allows you to disable additional hardware components and their associated drivers one by one to help find out the exact cause of the problem.
Troubleshooting system components involves a basic procedure that can be applied to any computer. This includes verification of the physical installation of the components, that the correct device drivers are installed, and that they are correctly configured to use system resources. These steps are discussed briefly in this section.
When you replace a component, you must verify that it is properly installed. You must follow the installation procedure and instructions provided by the manufacturer. Make sure that components such as adapter cards and memory modules are seated properly in their respective slots. Verifying the compatibility of adapters and input and output devices, and their proper configuration is very important to make sure that they will perform as expected with minimum troubles. Whenever you install or replace a computer component, test it thoroughly before handing it over to the end user.
Device drivers function as an interface between the device and the operating system. Make sure that you have installed a driver that is compatible with the operating system you are using. Incompatible device drivers can be easily uninstalled or updated using the Device Manager snap-in. Make sure that you are using the most current version of the device driver.
Every component in a computer requires certain system resources to interact with the CPU. These include the IRQ, DMA, and I/O addresses. In old computers, the resource settings were configured using jumpers on adapters. New computers have PnP-compatible system BIOS and operating systems, and most devices support PnP functionality. The PnP feature allows systems to detect system components and assign resources to them automatically.
If you suspect that a problem is caused by the incorrect allocation of system resources, you can use the Device Manager snap-in on Windows XP and Windows 2000 computers to see whether there are resource conflicts. You can view Resources by Connection or Resources by Type from the View menu to detect resource allocation conflicts. If you suspect that a particular device is causing trouble, you can open its Properties window and click the Resources tab to find out whether there are any conflicts. Windows Device Manager is discussed later in this chapter.
You should verify that the replaced or newly installed components or input/output devices are configured according to the instructions provided by the manufacturer. Improper configuration not only causes problems with the installed component but can also pose problems for other devices. For example, if you have manually configured incorrect resource settings for an add-on card, and some other device uses these settings, both of the components might stop responding. Incorrect configuration sometimes results in a system crash.
As a computer technician, you are expected to have a good quality toolkit for installing, removing, upgrading, or troubleshooting computers and associated peripherals. You can either go for a ready-made PC toolkit or buy different tools separately to make your own. Even when you buy a ready-made toolkit, you may still have to add a few tools that are specifically used for computers. The following is a brief description of some essential tools that will be very helpful in troubleshooting:
A multimeter is one of the most essential instruments used by computer technicians and electricians. It can measure voltage and current as well as test connectivity between various points inside the computer. Two types of multimeters are available on the market: analog and digital. Analog multimeters are cheap but are sometimes difficult to read. Digital Multimeters are a little more expensive but provide an accurate reading on an LCD screen. Multimeters are useful for checking short-circuits and measuring input and output voltage of power supplies.
A good set of screwdrivers with different types of bits is an essential part of your troubleshooting and repair kit. Most technicians prefer to have screwdrivers with long shafts that help reach the interior parts of the computer. At minimum, you must have two different screwdrivers: one with a flat bit and another with a Philips bit. Screwdrivers with magnetic bits are commonly used because they prevent screws from falling down into the computer case. It is not a bad idea to keep additional screwdrivers or at least a screwdriver with interchangeable bits.
Computers and other peripherals contain semiconductor chips that are very sensitive to static electricity. Static electricity can permanently damage semiconductors chips and adapter cards if not handled with caution. Antistatic wrist straps and antistatic pads (also known as antistatic table mats) should be used whenever you are working on computer parts. These products are very helpful in preventing damage to expensive computer parts due to a sudden discharge of static electricity from your body.
Loopback plugs are also known as loopback adapters. These small plugs are used with appropriate software to test the functionality of different ports on the computer, such as parallel, serial, and network ports. The accompanying software sends and receives electrical signals through the loopback plug to verify that the port is working properly. Loopback plugs and the associated test software differ from one manufacturer to another. They are very useful when you cannot test a particular port in an actual working environment. For example, if you do not have a printer, you can still test the functionality of the LPT1 port using a loopback plug.
Cleaning products fall into different categories that include cleaning solutions or chemicals, vacuum cleaners, and cleaning cloths. In some cases, you will need to take out an adapter card and clean its connection pins. Here is a brief introduction to cleaning accessories:
Soft, lint-free cloth or cleaning pads can be used for cleaning the monitor and other external parts of the computer.
A can of compressed air can be useful for cleaning without having to use any cleaning chemicals.
A handheld vacuum cleaner can replace the compressed air can when you cannot or are not allowed to blow out dust.
There are some special tools that are helpful in certain odd situations or with some special requirements. These include the following:
Helpful to inspect the dark areas inside a computer or a printer.
Useful for cutting wires and stripping their ends.
Required to attach two wires or to attach a wire to a printed circuit board.
Used to safely remove semiconductor chips from their sockets.
Useful for holding small parts or screws that fall inside the computer case.
Helpful in holding small parts where your hands cannot reach.
Used to cover unused wire ends.
Just in case you lose some screws during the repair/upgrade process.
Useful for storing and carrying spare parts such as adapters and memory modules.
It is always good to carry essential tools and even some extra tools when going out on a service call. Remember that the customer may not be able to provide you with any tools or accessories when you are badly in need. Asking the customer for a screwdriver or some other small tweezers leaves a bad impression about you and your company.
Preventive maintenance helps reduce the chances of computer breakdowns, and it improves overall system performance. It is essential to perform preventive maintenance at regular intervals. As a computer technician, you are expected to be aware of different forms of PM and how these measures can be implemented. In this section, we will briefly study some essential preventive maintenance tasks for specific computer components.
Display devices refer to computer monitors, which are an external part of the computer. Monitors produce heat when working and are also exposed to dust around the area where the computer is installed. If not cleaned regularly, dust accumulates on the screen and the case, and it also makes its way inside the monitor through the ventilation slots provided for keeping the monitor cool. Accumulated dust can also block some ventilation slots.
Monitors should be regularly cleaned using a lint-free cloth. You can also use a cleaning solution on the monitor cover but you must be careful not to let it spill over. Make sure that all ventilation slots are clear so that air can pass through them. When monitors are not to be used for longer periods, they should be kept covered.
A majority of computer problems are a result of the failure of the power supply. Care must be taken to ensure that the computer gets a clean and consistent power supply. Some of the preventive maintenance methods for power supply are as follows:
Use Uninterruptible Power Supply (UPS) to supply a clean and consistent voltage to the computer. UPS systems protect the computer from power spikes, surges, and sags that can cause significant damage to computer parts. In case of a power failure, the UPS can be very useful as it gives the user time to save his open documents or programs.
Power strips are useful for not only providing extra power slots but are also helpful in protecting the computer from sudden changes in voltage levels such as power spikes and sags. Some power strips come with a built-in fuse that blows off if there is a sudden voltage change.
A power surge refers to a sudden change of voltage in the power line. A surge protector is used to supply a constant voltage to computers and prevent damage due to power surges.
Regular cleaning of the power supply unit of the computer, especially the cooling fan and ventilation slots, helps lower heat during normal operation. You can use a handheld vacuum cleaner to clean the dust accumulated around the ventilation slots. Make sure that the computer is switched off and that the main cord is disconnected from the power source or wall socket.
Additional preventive maintenance measures for power supply include the following:
Always use 3-pin power cables with computers and peripherals to provide the ground connection.
Provide a separate dedicated circuit when there are a large number of computers and peripherals.
Turn off computers and then cut off the main switch during storms and thunderstorms.
Turn off the main switch when there is a blackout. When the power returns, there might be a sudden voltage spike causing damage to computers.
All input devices, including keyboard, mouse, and scanners, should be kept covered when not in use. Keyboards collect dust from the surrounding areas, and as a result, the keys start having intermittent jamming problems. Dust accumulated on the sides of the keys can be blown out using compressed air. Care should be taken if you use a vacuum cleaner. A powerful vacuum cleaner can knock off key tops from the surface of the keyboard. You can also use a soft brush to get rid of the dust accumulated around and between key tops.
There are a number of preventive maintenance methods for storage devices, each suitable for a particular type. The life and performance of storage devices can be enhanced by using some standard procedures. Even if the computer is located in clean surroundings, cleaning internal parts of the computer regularly does help extend the life of its components. Some of the preventive maintenance procedures for storage devices are as follows:
Hard disks should be defragmented regularly and should be cleaned of unnecessary temporary files. You can use built-in operating system utilities such as Disk Defragmenter (defrag.exe) and Disk Cleanup. Additionally, you can check for and fix bad sectors in disks using the Check Disk (chkdsk.exe) utility.
CD and DVD drives rely on laser beams and an optical lens to read and write data. Dust accumulates on the lens surface that causes intermittent disk read/write problems. You should regularly clean CD and DVD drives using appropriate lens cleaners.
Tape drives should be cleaned using tape drive head cleaners.
Floppy disk drives should be cleaned using a floppy disk drive head cleaner.
Motherboards, add-on cards (adapters), and memory modules are all thermally sensitive devices. Ensuring that the computer is operated in an area where temperature, humidity, and dust are controlled helps enhance their performance, extend their life, and reduce breakdowns. The CPU and other semiconductor chips on these cards produce heat during normal operation. While a CPU has a dedicated heat sink and an exhaust fan to keep it cool, its heat ultimately has to be blown out of the computer case. If this is not done, the temperature builds up inside the computer and can cause damage to these components.
Make sure that all the cooling fans are working properly, that dust is not accumulated around them, and that the ventilation slots of the computer case are not blocked. Regularly blowing out dust from the top of motherboards, from CPU fans, from memory modules, and from adapter cards will ensure that problems are minimized. Cooling fans usually get jammed due to the accumulation of dust around the blades and walls.
No matter how many ventilation slots and cooling fans exist within a computer, it is essential that the external cooling factors should also be taken care of. If the computer is located in an area where temperature is not controlled and no proper ventilation exists, it will eventually heat up after prolonged hours of operation. You must make sure that the computer is operated in a room where adequate air-conditioning and ventilation is available. Care must also be taken that the computer is placed at some distance from walls so that the power supply fan can blow out the internal heat. Placing the computer very close to the wall blocks airflow from the power supply.
Humidity also needs to be mentioned in this section. Computers should be located in areas with moderate humidity. Very dry areas or areas with too much moisture affect the life and performance of computers. If the air around computers is too dry, it will cause static electricity to build up, which may damage expensive computer parts.