COMTECH Page 1 of 55 Pages
COMPUTER TROUBLESHOOTING SAFETY PRECAUTIONS
There is no such thing as effective troubleshooting if safety has not been met. The effectiveness of the troubleshooting comes only if there are no injuries, tool and equipment failure due to mishandling, peripheral malfunction due to misdiagnoses and mishandling and other things that marks the big 7-letter word - FAILURE . So what should you do to be able to do "Effective Troubleshooting" ? Follow the three most important things below to find out how and what to learn!
#1 What you wear might save you!
Yes you did not read it wrong. What you wear really matters specially if we are dealing with safety. In big companies, overall uniforms, laboratory gowns and technicians' gown are required to be worn in their work areas. As freelance technicians, we don't strictly follow company protocols but at least we must ensure safety through using proper clothing.
What is appropriate for every computer technician to wear are clothings that won't catch fire fast like cotton. Nylon clothes should be avoided. One must also
wear clothes with shorter sleeves to keep the connectors and other things in the system unit from clinging to your clothing. Buttoned shirts and clothing with dangling laces or similar should not be worn during computer troubleshooting.
Please don't use very loose clothes like the hip hop crews wear, rings, necklaces, dangling earrings, bracelets, and similar objects as well.
#2 Electro-Static Discharge is not your bestfriend
ESD is a form of electricity that can wreck havoc to your computer peripherals or its components. How do you get ESD's? Just everywhere, upon walking when you rub your shoe against a carpet, or combing your hair or just anything you rub against or touch. To be able to avoid damaging your computer system unit, you must discharge the ESD by using the ESD Wrist Strap while working with your computer.
But what if you don't have any ESD Wrist Strap? Don't worry before opening up your unplugged computer system, touch any unpainted portions of the system
COMTECH Page 2 of 55 Pages
unit for a few seconds. This can significantly dissipate the ESD that you have in
your body. Also consider using Anti-Static Mat while working your your computer to ensure safety against Static Electricity. But again, grounding yourself to the computer's chassis is enough to drain off the ESD's.
Since ESD's can damage computer peripherals and components, it is best to store your removed components and peripherals in Anti-Static Bags.
#3 Working Safely with Electricity
Whether your home outlet is 110 or 220 volts Alternating Current (AC), it can potentially kill you. But before working safely with the insides of your computer, let us be familiar first with the outsides of the computer.
In powerlines, the electricity that flows through the lines are not perfectly stable. The voltage may rise and fall and this action of the unstable voltage is called a voltage spike. Though most devices can operate even with voltage spikes, your computer cannot endure this spikes. What your computer eats is a stable supply of electrical current. The Automatic Voltage Regulator (AVR) does this job. It regulates or flattens out the AC flow of electricity to be fed to your computer. After the AVR, your computer receives the regulated 110 or 220 V AC electricity into your Power Supply Unit (PSU) and converts it into Direct Current (DC) like 12, 5, and 3.3 V respectively.
So we have in mind that the electricity we get from the outlet is 110 or 220 V, unregulated and as it passes though the AVR it is still 110 or 220 V but the spikes are now removed - and still dangerous. As the electricity from the AVR is received by the PSU, it is converted to DC and is now less dangerous. In other words if you
are working with your computer, turn off your system unit and unplug the power cord from the AVR. If you might say that the DC current of the motherboard is
small and can not cause you harm, consider that the components of your computer are sensitive to electrical shortages.
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COMPUTER SAFETY DO AND NO LIST
Do's
- Wear anti-ESD Wrist Strap and if there is none, drain off the ESD by touching the unpainted part of your system unit. ESD's are known to destroy discrete devices like your RAM, BIOS, Chipsets and other components of your
motherboard. So take this precaution seriously.
- Wear proper clothing. Use cotton and short-sleeved clothes during work. If ever the computer your working on catches fire, cotton most likely better resist
burning than nylon clothes.
- Turn off the system unit and unplug the power cord from the AVR every time
you will be working with your computer. Keep in mind that there is a constant 5
volts DC electricity even if your computer is turned off with cords unplugged and AVR not turned off.
- Keep screws together. If some screws unintentionally goes on the motherboard, that will be disastrous! Short circuit will likely be a big possibility if screws or other similar small metallic objects are misplaced. It is best to keep a small canister to contain the screws or just put the screws back where they were taken.
- Clean your tools and equipment before and after use. Take care of your tools because they will also take good care of you. Tools and equipment in good condition lessens accident.
- Clean your system unit before fixing it.
- Fix your computer if it is broken. Yes, don't assume that the computer is broken lest you're sure it really is. You might add up or make the problem yourself rather than to fix it.
- Backup files and drivers before anything else. Files costs millions of dollars to other clients. Our main concern before everything else is our clients' files. Fixing the hardware part of the computer is just next to saving and retrieving the files that the computer may contain. So always prepare a large backup media for your clients.
COMTECH Page 4 of 55 Pages - Have a documentation on each computer being fixed. A documentation will be your personal troubleshooting database. This will be a handy future troubleshooting reference. Your documentation will also serve as your guide as you go on with your troubleshooting.
- Do make use of the comfort of time in computer troubleshooting. Do not be in a hurry when fixing a computer. If you can't finish the fix on that day, let the day pass and fix it by the morning. Mistakes occur because of distraction and of the lack of concentration. So slow down cowboy and fix that computer slow and accurate.
No's!
- Forgetting everything with the Do's and leaving the brain on the bed while working. Just remember all those Computer Safety Do's and I assure you, you'll never have to remember the No's.
STEPS FOR A SAFE AND SUCCESSFUL SYSTEM UNIT ASSEMBLY AND DISASSEMBLY
You might think that disassembly and assembly of the system unit is easy. Yes it is provided that you have done it correct and safely. The first thing that every computer technician should keep in mind is SAFETY. You must think that
electrocution and nasty cuts are the most common injuries a computer technician might have and we need to avoid it by following simple safety procedures.
To disassemble and assemble a computer is integral as being a Computer
Hardware Servicing Technician.
Aside from electrocution, we must also think that the computer that we are about to disassemble requires care. Safety of the equipment must also be considered. Not only thinking of the computer's safety but also to that of your tools. Your tools are your best friends and you need to take good care of them so they in return can make your job easy and fast. Example, if you just leave your software installer anywhere then accidentally falls to the ground and accumulates
scratches? Do you think you can still use the installer again?
COMTECH Page 5 of 55 Pages must be responsible to take our part to take care of the environment. What
things does computer technicians do that might have ill effects on the
environment? Printer inks, cut wires, PCB's, in general electronic wastes. And these electronic wastes are the hardest type of waste to recycle. So be
responsible as a computer servicing technician. So listed below is the checklist for a safe and successful disassembly and assembly of the computer.
Steps to a Safe and Successful Disassembly and Assembly of a System Unit To Disassemble
1. Prepare all your tools. a. Long Philip Screw Driver b. Rubber Eraser
c. Soft Wide Bristle Brush
d. Paper and Pen for documentation
2. Before opening the system case, be sure to turn off the system unit. Turn off and unplug the AVR from the wall socket as well. After that, unplug all the cables connecting to the back of the system unit. After clearing all the connected cables, put the system unit on an empty working table.
3. Touch the unpainted part of your system unit with your bare hands to remove the ESD of your body. This is an important part before opening your system case. You might destroy your RAM, Chipsets and other components of your
motherboard.
4. Remove the screws of the side cover opposite to the side where the ports are. By most system cases, if you are facing the back of the system unit the right side cover is to be removed. Return the screws back to the screw holes to avoid losing them.
5. Once the side cover is removed, turn your system side down where the opened side of the system unit should be facing upward where you can comfortably look down on the inside of your system case.
COMTECH Page 6 of 55 Pages thing we need to do is remove the power supply. To be able to remove the power supply, remove first the molex connectors (the white plastic connector at the tip of the wires of the power supply) or the motherboard power connector, drive power connectors, the floppy drive power connector, the sata power connectors and the four pin 12-volt motherboard connector. With all power connectosr are removed from the motherboard and drives, the power supply is now ok to be removed as well. Always have the removed components placed in a remote and safe place away from where you are performing computer disassembly.
7. With the power supply removed, the data cable should be removed next. This includes IDE, SATA, and floppy drive cables. Secure the removed data cables.
8. Next to remove are the RAM, Video Card and other card peripheral
components. Again have them secured in a safe place and put the screws back. Clean the connector edges of the card peripherals by rubbing the gold colored edge moderately with a rubber eraser then brushing off the shredding. Do not attempt to clean the edge by blowing or brushing it off with your fingers. Our body is acidic and you might only cause the edges to tarnish faster.
9. Remove all drives. This will include your hard drive, cd/dvd drives, and the floppy drive.
10. Since all peripherals where removed, the next thing to do is to remove the front panel connectors. This will include the USB, Front Panel (FP) and Audio header. If you are not sure of which connector is being match to, write down or document the connections and orientation of the connectors before removing them from the headers. Remember that not all motherboards have the same header configuration so be careful and watchful while documenting.
11. After removing the header connectors, we are now ready to remove the motherboard. To remove the motherboard, locate first all the screws and lightly unscrew all screws alternately. With this technique, we are reducing the risk of warping or bending our motherboard. It may not have a large impact on the bending of the motherboard but still it does have even a little. Upon lightly loosening all screws, remove all screws then. Remove the motherboard by
carefully and lightly pulling it away from the I/O shield. Why? because we need to free the ports that are fitted from the holes in the I/O shield. After freeing the
COMTECH Page 7 of 55 Pages motherboard ports from the I/O shield holes, lift up the motherboard and put it on the safe place.
12. Clean the system unit chassis with your brush, also clean your motherboard and the rest of the peripherals being removed.
To Assemble
1. Provided that all peripherals are clean and ready. We are now going to
assemble your computer. In assembling back your computer, what we have done during disassembling is just doing the reverse order to assemble it. Since the motherboard was last to be removed, it should then be the first to put back. Remove the retaining screws from the standoff screws of the motherboard and let the motherboard seat on it with the ports facing out towards the I/O shield. Lightly push the motherboard to set its ports to the holes of the I/O shield. Put the retaining screws on the motherboard screw holes but do not tighten it yet. Now be careful in doing this one and if this is your first time doing it, it is best if you lend a hand for assistance. Lightly push the motherboard towards to I/O shield and lightly tighten the motherboard retaining screws alternately until all screws are tight enough but not too tight. This is to ensure that your ports are protruding correctly out of the I/O shield.
2. Once the motherboard is secured, put back the FP, Audio, and USB header connectors as you will be using your documentation for reference.
3. Put back the drives to the correct drive bays.
4. Connect back the RAM, Video Card and other card peripherals to its proper slot inserting it properly and some cards will require screws to be secured.
5. The data cables (IDE, SATA, floppy cable) should be connected to its proper headers and drives. Remember the proper configuration of the placement of the cables specially if you are dealing with the IDE cables.
6. After the data cables are properly connected, put back the power supply and secure it with the screws you removed earlier. After securing the PSU to the chassis, connect the power connectors to the drives and the motherboard.
COMTECH Page 8 of 55 Pages 7. Once all peripherals are connected properly, have a final inspection by visually checking for loose connection or improper connection. Once the system unit connections are thoroughly checked and verified, connect the keyboard; the monitor, and the power connector then power up the computer. This initial powering up of the computer while the side cover is open ensures us that everything is ok before putting back the side cover. In case something goes wrong, we can accessibly correct the problem right away. If everything is fine shutdown the computer, unplugged the AVR and remove the cables connected to the back of your computer. Put the side cover back.
8. Put the assembled computer back to its place and connect the rest of the cables and connectors. Power it up and see if there are unusual effects of your disassembling/assembling procedure done earlier.
Remember SAFETY. Do not neglect it. Neglect can cause catastrophic effects.
DISASSEMBLE A COMPUTER - EASY AND DETAILED PROCEDURE
To disassemble a computer may be a very daunting task to anyone - at least to people with no or little knowledge or experience. Does this mean it includes you? Probably not, you found our blog and you will be learning how to do things right and easy. Yes! By reading and following the detailed instructions that we will be providing, you will be able to disassemble a computer correctly and easily.
Before we begin, allow yourself to ponder with these questions.
Is it necessary to disassemble my computer? Am I sure I can get things right?
Will I be able to put this thing back in one piece again?
By answering the questions above, you will be able to evaluate yourself whether you are confident enough to do it (or whether your way or based on other
reference like this blog)? If you aren't sure enough, just read on and learn before doing any actual application.
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Here are some things you need to consider before you begin to disassemble your computer
1. Safety - Safety should be a priority specially that you are dealing with
electricity, precious data, and expensive computer parts to handle. Find out more about computer troubleshooting safety here.
2. Tools - Though are are many tools a computer technician should have, we can however do the job well with fewer tools. A long philip screwdriver, a wide bristle brush, and a rubber eraser. This are the basic tools need to disassemble a
computer.
3. Notes - What's a note for? If you are to disassemble a computer and unsure of which things is first to remove and how it is positioned, sometimes you get
disoriented of the proper procedure and end up having the computer dumped in a bin. Note taking is essential so that it will serve as your personal guide. Believe it or not, I have been working as a computer technician for more than five years now and still maintains a notepad.
All are now set for the procedure. Again think safety, have the appropriate tools, and have a notebook alongside to take down important notes. Let's begin to to disassemble your computer or system unit.
1. Find a suitable insulated table (or wooden table) to begin with your work.
2. To avoid any accidental electrocution, be sure to unplug your computer from the AVR. And then remove the other connectors at the back panel or back side of your computer (where you can see some wires going to your mouse, keyboard, and others) leaving the computer or system unit totally detached. At this
moment, you won't be needing any tool for the removal of the components.
3. We are now ready to remove the side covers. At the back side of your
computer you should see some screws locking the covers, but which side cover should we remove? Can you see where the ports are located? If they are located on the left side, then you need to remove the right side cover and vice versa. Use your Philip screwdriver to do this.
COMTECH Page 10 of 55 Pages 4. Once the correct side cover is removed, lay down the computer on the table so that you will be seeing the insides from above. In this manner, it will be a lot
easier to remove the components.
5. You may now begin to remove the computer's components. Here is a short list of which components should be first removed.
1. Power Supply Unit (PSU) - remove the molex connector or power cablings (with
red,yellow,black,orange wires) from the board and drives. When you remove the connectors, try to swivel it along its length.
2. Data Cables (IDE and SATA) - carefully remove these cables by swiveling it. Removing all cables clears the space for us to work things easier.
3. Card Peripherals - this should include removing the RAMs, Video Card, Modems, Sound Cards, and other card peripherals. Be sure to remove them properly
4. Drives - DVD,Blue Ray, and hard disk drives should be removed after the card peripherals. Be sure to put back the screws back to the drives upon removing it
5. Front Panel Connectors - since every motherboard has its own configuration, we need to take down notes of the proper orientation of the pins. But if you memorize it, the better. Asus and intel board are almost having the same front panel pin configuration. Other boards like ECS and IBM boards have the same pin configuration as the latter. This is where we will be taking notes, draw the pin configuration if possible.
6. Motherboard - be very careful in removing the motherboard, avoid scratching any surface on the motherboard as there are many surface mounted components soldered on it. And after removing the motherboard, put it in an area where there is insulation on its bottom or best, put it in a anti-static bag.
7. Processor (CPU) - removing the processor requires a bit of technical skill
6. After all the components are taken apart, clean them with the brush that you have. Dust will accumulate heat and can destroy your computer's components.
7. Do not forget to clean the connector edges of your peripheral cards. The connector edges are those shiny gold-colored edges of your RAM, Video card, and other similar components. Use an eraser to do the cleaning but if you have a flux cleaning agent, that should do the job better. Using an eraser, just lightly
COMTECH Page 11 of 55 Pages scrub on the connector edges and then brush off the shredding. Remember to always clean the computer every time you take it apart.
This is how a computer should be disassembled. Again safety,proper tools, and note taking is your arsenal. Drop your fear, start learning and to disassemble a computer is just one of the many things you have to learn in troubleshooting computers. If you have any question about computer disassembly, please do not hesitate to comment and I will help you out in no time.
BEGINNER'S GUIDE TO TROUBLESHOOTING COMPUTER HARDWARE
If you are trying to learn how to fix computers and don't know where to start, this is the right place for you. When learning how to fix or troubleshoot computers, one must have a trusted guide and clear instructions to follow.Computer
hardware servicing is not that hard as you may be thinking and not as easy as
some people claim. A step by step approach of teaching should favor the student and that is what this Beginner's Guide to Troubleshooting Computer Hardware is promoting for you to learn computer hardware servicing fast, easy, and free.
Before we proceed with our tutorial, let us first assess things that you currently learn about computers and yourself.
1. Are you familiar and practicing occupational health and safety (OHS) when working with computers?
2. Do you know how to operate a computer? 3. Are you afraid of electricity?
4. Do you have the passion to learn on how to fix computers? 5. Have you ever tried tinkering or opening an electronic device? 6. Are you resourceful enough?
7. Do you have patience?
Asking these questions to yourself gives you a hint of what a computer hardware service technician's attributes are. If ever you say no for any of the questions above, it is ok. Read on and you will know why I am saying it really is ok.
Safety Is A Priority
COMTECH Page 12 of 55 Pages even if you are just sitting and browsing the web with your computer, radiation is already softly cooking you. Your monitor emits small amounts of radiation
tolerable by own body but radiation is still radiation. Wonder why your eyes gets tired and sores a little when using computers for some prolonged usage of your computer. Safety must be observed.
Now how about if your are to fix a computer? Accidents may happen like
electrocution, cuts, dropping and damaging the tools and equipment, blowing or frying the motherboard and other peripherals if safety is disregarded. To make things short, computer safety must be followed.
I Know You Can Operate A Computer
This might be a silly statement but what I am trying to imply is different. Of course I know you can operate a computer that is why you are reading this article. But sometimes, what we think we already know isn't enough. Keyboard shortcuts, using process names to open programs, use of batch files and the command prompt, tweaking using the registry editor, and so many things are some of the operation that you should be familiar. And I am not saying that you must know everything about operating the computer first before learning how to fix it, you must somehow "learn" by process. Learn more computer terms by reading
ebooks. We will soon be providing ebook downloads soon or just email me to ask for a copy.
Fear Not For Electricity Is Your Friend
During my years as a freelance computer hardware serviceman, I often see
students having On-the-Job Trainings (OJT)in computer shops just standing by the corner and watching seasoned computer technicians doing something. And when a seasoned technician asks for assistance from the trainee, it is evident that the trainee shows hesitation with plugging into sockets and molex power connectors. It is not good to hesitate in doing things because uncertainty surely leads to
disaster.
Fear of electrocution is common among newbies. I could remember during my college days when my Building Wiring and Electricity instructor tried to have us touched a 220 live wire just to let us feel electricity. I never touched when he said so but when we were asked to do our practical examination by building a two-way switch on a large dashboard, I accidentally touched a bare live wire! A shock
COMTECH Page 13 of 55 Pages was sent up to my armpit and I was so careful about electricity ever since.
You can't fix a computer without electricity, just be very careful in using it.
Be Passionate About Fixing Or Troubleshooting a Computer
It's just like having a girlfriend. If you are not dedicated and passionate with her, you will be throwing stones at each other by the morning! You see if you love what you are doing, you can do things right and makes you genuinely happy. If you feel that troubleshooting computers is not the thing for you, then quit. Do other stuff that you feel you love to do and you surely will be good and happy with it.
Be passionate to troubleshoot and learn computer hardware servicing. You can only be a good computer hardware technician if you are passionate on what you are doing. Doing things right with eagerness to improve is the key to be a
successful learner.
Tinkering And Being Curious About The Insides Of An Electronic Device
If you love to open electronic devices or just anything you are curious at, is a good sign that you are an eager learner. It also shows that you have interest in the inner workings of a machine and wants to analyse how a thing works. In
troubleshooting computer hardware, it is important that you can analyse how the parts are positioned or being attached to. Computer hardware servicing may seem difficult, very technical, and boring but it is actually easy, handy, and exciting!
Be Resourceful, Not Everything You Got Is Enough
Learning really takes time. You just can't just click any links from the web and expect to learn something. Sometimes you must choose those which are worth knowing and reading. Sometimes clicking some links in a site brings you to good pages and will take away your blues trying to learn.
So be resourceful, don't just get stuck with few resources. Research and don't be afraid to learn. Experience will also bring more knowledge. Try to apply what you have learned and you will surely thank yourself.
Be Patient At All Times
COMTECH Page 14 of 55 Pages there will be times when you can't fix the machine right away. You need to give yourself a time to regroup and think of a better solution.
Have you thought of these things? If you think you have or able to develop the attributes discussed above, then you already becoming a good computer
technician in the process. Learning is a process, it takes enormous effort and time. So let me give you a draft on what things you should be learning to become full fledged computer hardware servicing technician.
What You Should Learn About Computer Hardware Servicing
1. Occupational Health and Safety Procedure 2. Basic Computer Operation
3. Understanding Binaries and Logic Gates
4. Introduction To Computers - Components of the IT System
5. The System Unit - Hardware Component Functions and Description - Motherboard
- Central Processing Unit
- Random Access Memory, Read Only Memories, and Basic Input/Output System (BIOS)
- Storage
- Operating Systems, Tools, and Utilities - Installation - Networking
- Troubleshooting Techniques
TROUBLESHOOTING PROCEDURE
Before testing the system unit, we must first ask few questions to the owner of the system unit to give us some clues on what and when's regarding the
computer problem encountered. Remember that first hand information about the computer problem encountered by the owner or user is the most
near-reliable source of idea on what really is the problem of his or her computer. But
be warned, I have had said near-reliable because most users being asked lies on the details fearing that the blame is on them. You must ask them in low tone, soft, non-vindictive, and non-agitating manner. The details they give might be useful for your approach introubleshooting.
COMTECH Page 15 of 55 Pages checking and testing the system unit. Be sure to physically check
the peripherals first before testing. Try to see if there are missing, blown, or
poorly attached cables and peripheral cards. Then after a thorough check, test the system unit and do a detailed observation.
SAFETY PROCEDURES
There are certain procedures you should follow when you are installing items in your system. Below is information to avoid damage to your system or/and yourself.
Before entering the computer, move computer off the carpet (for static
purposes). If your not able to then try not to move on the carpet to keep the static from building.
Disconnect all cables including power cord. I can't stress this enough. Remove the power cord, monitor, keyboard, mouse, phone line, network cable, speakers, printer, scanner, USB cables, cable modem, DSL modem and anything else that is connected. (it should look similar to the picture below)
With everything disconnected, push the power button for 5 seconds. (with
power cord disconnected). The computer can store power even with the power cord disconnected. Pushing the power button drains that power (only if the power cord is disconnected). VERY IMPORTANT!!!
Touch something metal on the case of the system to release any static build
up in your body.
Computers are the best dust collectors. Do not blow on the dust with your
breath. Your breath has moisture and electronics hate moisture.
If you want to clean the inside of the system of dust, use compressed air
that is designed for electronics.
While using the compressed air, do not hold down the button. Not only will
the can get cold, moisture will also form. Use quick short bursts.
When handling parts, do not touch the bronze teeth. Hold the parts on the
edges if at all possible.
If you are troubleshooting noise issue, some people will stick a pencil or other objects in the fan to stop the fan from turning to see if the noise goes away. DON'T DO THAT! The fan might shatter the pencil, cause a fire, cause electrical shock or short.
If you disconnect the cable that goes to the processor fan to check for
COMTECH Page 16 of 55 Pages
Be careful while inside system, the system has sharp edges.
Never put your hands inside system when the system is either plugged in or
turned on.
Some computer desks have a compartment that you can put your
computer in. Make sure that compartment is well ventilated. If it is not ventilated, it can fry the system. If it is not well ventilated, you can drill holes in the desk to give it ventilation, or you can install a small fan in the desk that will circulate air.
Do not connect or disconnect cables while the system or device is turned on. (unless it is USB. USB can be disconnected or connected while system is on). Equipment can be damaged by this.
Keep these important tips in mind as you work inside your computer:
Remember to Flip the Switch
Always, always, always remember to turn the power off before servicing anything. This should always be your first step. Do not even open the computer case unless the power is turned off. Many computers have a number of lights inside that serve certain functions so check to see that no lights are on. If any are still on then the power is probably not completely off.
Many power supply units have a switch on the back, killing power to the device and ultimately the rest of your PC. If your PSU has one, be sure to turn it to the off position.
Unplug for Extra Safety
As a second precaution, it is wise to unplug the computer from the wall or power strip. If there was any doubt as to whether the computer was off before, it's settled now.
Avoid Smoke and Smells
See smoke coming from the power supply or inside the case or smell a burning or solder scent? If so:
1. Stop what you're doing immediately. 2. Unplug the computer from the wall.
3. Allow the PC to cool or discharge unplugged for at least 5 minutes.
Finally, if you know which device was generating the smoke or smell, remove and replace it as soon as you can. Don't try to repair a device that's been damaged to this extent, especially if it's a power supply.
COMTECH Page 17 of 55 Pages
Remove Hand Jewelry
An easy way to get electrocuted is to work around a high voltage device like a power supply with metal rings, watches, or bracelets on. Remove anything conductive from your hands before working inside your computer, especially if you're doing something like testing your power supply.
Avoid Capacitors
Capacitors are miniature electronic components contained in many of the parts inside a PC. Capacitors can store electric charge for a short while after the power is turned off so it's a wise decision to wait a few minutes after pulling the plug before working on your PC.
Never Service the Non-Serviceable
When you come across labels that say "No serviceable components inside" don't take it as a challenge or even a suggestion. This is a serious statement.
Some parts of a computer are just not meant to be repaired, even by most
professional computer repair persons. You will usually see this warning on power supply units but you may also see them on monitors, hard drives, optical drives and other dangerous or highly sensitive components.
Help your computer live longer, perform better, and avoid debilitating crashes.
INTRODUCTION TO PC COMPONENTS
Here you will learn computer hardware tutorials introduction, basic pc components, networking devices, ram, vga, monitor and printer etc. Computer hardware is the physical part of the computer including the digital circuits inside the computer as opposed to the software that carry out the computing instructions. The hardware of a computer is unlikely to change frequently unless due to the crash or for upgrading them. The devices that is capable of storing, executing system instructions and controlling other logical outputs.
Hardware comprises all of the physical part of the computer such as Monitor, CPU, motherboard, ram, CD-Rom, printer, scanner, hard disk, flash drive (AKA pen drive), processor, pci buses, floppy disk, power supply, VGA card, sound card, network interface card, peripherals, joystick, mouse, keyboard, foot pedal, computer fan, camera, headset and others.
On the other hard software is a logical part of a computer and is used to carry out the instructions, storing, executing and developing other software programs. A
COMTECH Page 18 of 55 Pages typical PC consists of a case or chassis in the desktop or tower case and these components.
CHAPTER 1: INTRODUCTION
Your PC (Personal Computer) is a system, consisting of many components. Some of those components, like Windows XP, and all your other programs, are software. The stuff you can actually see and touch is hardware.
Hardware
The hardware are the parts of computer itself including the Central Processing Unit (CPU) and related microchips and micro-circuitry, keyboards, monitors,case and drives (hard, CD, DVD, floppy, optical, tape, etc...). Other extra parts called peripheral components or devices include mouse, printers, modems,scanners, digital cameras and cards (sound, colour, video) etc...
The devices which are Necessary to assemble a computer
• Motherboard • Processor • Memory • Hard Drive
• Video Card (if motherboard didn't come with it)
• Sound Card (if motherboard didn't come with it)
• Modem and/or Network Card • Floppy Drive
• CD-Rom
• Keyboard and Mouse • Case And Power Supply • Monitor
CHAPTER 2: PROCESSOR
The Central Processing Unit, Which is often referred to as the “Processor” is the
COMTECH Page 19 of 55 Pages instructions needed to make your computer run. Without this chip, no other function of the PC is possible. The processor is attached to the motherboard (Processor slot).
The speed of the CPU
The computer's speed or clock rate is integral to its overall design. The computers clock rate is the frequency at which it can execute a set of instructions. Computer clock rates are measured in Megahertz (million of clock ticks per second).
There are two types of speeds that should be considered when evaluating the system performance:
Internal clock speed – Is the speed at which the processor can obtain information
within itself, like with internal cache and registers. (Pentium III 800 MHz. the 800 MHz is the internal clock speed)
External clock speed – Is the speed at which the CPU communicates with
components outside itself.
Some commercially available processors
• Pentium I-IV • Celeron • Athlon • Duron • Cyrix C3 • Itanium (64 bit) • Opteron (64 bit)
How to Choose a CPU
When you are choosing one CPU always consider your computing needs when selecting a CPU. If you want to do simple word processing or general computer tasks, go for the budget or low end processors. If you are more into gaming or do CPU intensive work like video editing, go for a mid-range or high-end processor.
CHAPTER 3: MOTHERBOARD
Chapter 3.1: Motherboard
The motherboard is the main circuit board inside your PC. Every components at some point communicates through the motherboard, either by directly plugging into it or by communicating through one of the motherboards ports. The motherboard is one big communication highway. Its purpose inside your PC is to
COMTECH Page 20 of 55 Pages provide a platform for all the other components and peripherals to talk to each other.
Motherboard
MOTHERBOARD COMPONENTS
The motherboard holds all the major logic components of the computer. Here we are going to see with no particular order, some of those major motherboard componets and their function in a computer or to be more precise in your computer.
A core 2 Duo Intel Processor
CPU- Central Processing Unit
It is also known as the microprocessor or the processor. It is the brain of the computer, and it is responsible for fetching,
decoding and executing program instructions as well as performing mathematical and logical calculations.
COMTECH Page 21 of 55 Pages The processor chip is identified by the processor type and the manufacturer; and this information is usually inscribed on the processor chip e.g. Intel 386, Advanced Micro Devices (AMD) 386, Cyrix 486, Pentium MMX, (old processor types) Intel Core 2Duo e.t.c.
If the processor chip is not on the motherboard, you can identify the processor socket as socket 1 to Socket 8, LGA 775 e.t.c. This can help you identify the
processor that fits in the socket. For example a 486DX processor fits into Socket 3.
Memory Modules
Main Memory / Random Access Memory (RAM)
Random access memory or RAM most commonly refers to computer chips that temporarily store dynamic data when you are working with your computer to enhance the
computer performance. In other words, it is the working place of your computer where active programs and data are loaded so that any time time the processor requres them, it doesn't have to fetch them from the hard disk which will take a longer access time.
Random access memory is volatile memory, meaning it loses its contents once power is turned off. This is different from non-volatile memory such as hard disks and flash memory, which do not require a power source to retain data. When a computer shuts down properly, all data located in random access memory is returned back to permanent storage on the hard drive or flash drive. At the next boot-up, RAM begins to fill with programs automatically loaded at startup, and with files opened by the user a process called booting.
BIOS Chip
BIOS- Basic Input Output System
BIOS is a term that stands for basic
input/output system, which consists of
low-level software that controls the system
hardware and acts as an interface between the operating system and the hardware. Most people know the term BIOS by another name—
device drivers, or just drivers. In other words, the BIOS is drivers, meaning all of
them. BIOS is essentially the link between hardware and software in a system. All motherboards include a small block of Read Only Memory (ROM) which is separate from the main system memory used for loading and running software.
COMTECH Page 22 of 55 Pages On PCs, the BIOS contains all the code required to control the keyboard, display screen, disk drives, serial communications, and a number of miscellaneous functions.
The system BIOS is a ROM chip on the motherboard used by the computer during the startup routine (boot process) to check out the system and prepare to run the hardware. The BIOS is stored on a ROM chip because ROM retains information even when no power is being supplied to the computer.
CMOS Battery
CMOS-Complimentary Metal Oxide Semiconductor
Motherboards also include a small separate block of memory made from CMOS RAM chips which is kept alive by a battery (known as a CMOS battery) even when the PC’s power is off. This prevents reconfiguration when the PC is powered on.
CMOS devices require very little power to operate.
The CMOS RAM is used to store basic Information about the PC’s configuration e.g.
Floppy disk and hard disk drive types
CPU
RAM size
Date and time
Serial and parallel port information
Plug and Play information
Power Saving settings
The Other Important data kept in CMOS memory is the time and date, which is updated by a Real Time Clock (RTC).
L2 Cache on an old Motherboard
Cache Memory
It is a small block of high-speed memory (RAM) that enhances PC performance by pre-loading information from the (relatively slow) main memory and passing it to the processor on demand.
COMTECH Page 23 of 55 Pages the processor) which is referred to as Level-I cache memory or primary cache memory. This can be supplemented by external cache memory fitted on the motherboard. This is the Level-2 Cache memory or secondary cache. Some CPUs have both L1 and L2 cache built-in and designate the separate cache chip as Level
3 (L3) cache.
PCI Slots
Expansion Buses
An input/output pathway from the CPU to peripheral devices typically made up of a series of slots on the motherboard. Expansion boards (cards) plug into the bus. PCI is the common expansion bus in a PC and other hardware platforms. Buses carry signals, such as data; memory addresses, power and control signals from component to
component.
Expansion buses enhance the PCs capabilities by allowing users to add missing features in their computers in form of adapter cards that are slotted in expansion slots.
The different types of buses include PCI, ISA, and EISA expansion bus.
Chipset
A chipset is a group of small circuits that coordinate the flow of data to and from key components of a PC. This includes the CPU itself, the main memory, the secondary cache and any devices situated on the buses. The chipset also controls data flow to and from hard disks, and other devices connected to the IDE
channels. A computer has got two main chipsets:-
The NorthBridge (also called the memory controller) is in charge of
controlling transfers between the processor and the RAM, which is way it is located physically near the processor. It is sometimes called the GMCH, for
Graphic and Memory Controller Hub.
The SouthBridge (also called the input/output controller or expansion
controller) handles communications between peripheral devices. It is also
called the ICH (I/O Controller Hub). The tem bridge is generally used to designate a component which connects two buses.
Chipset manufacturers include SIS, VIA, ALI, OPTI e.t.c.
COMTECH Page 24 of 55 Pages
Motherboard Form Factors
The motherboard form factor describes its general shape, the type of case and power supply it can use, and its physical organization (layout of the motherboard). It is what we are going to have a look at in this hub.
Computer Bus Architecture Types
A bus is a common pathway through which information is connected from one component to another. This pathway is used for communication and can be established between two or more computer components.
DDR1, DDR2, DDR3: Navigating The RAM Maze
Choosing the proper DDR-type for your PC is critical. The wrong choice can drastically bottleneck your system. Here is a full guide to picking the right DDR for your CPU.
Cpu Clock
The clock synchronizes the operation of all parts of the PC and provides the basic timing signal for the CPU. Using a quartz crystal, the CPU clock breathes life into the microprocessor by feeding it a constant flow of pulses.
For example, a 200 MHz CPU receives 200 million pulses per second from the clock. A 2 GHz CPU gets two billion pulses per second. Similarly, in a
communications device, a clock may be used to synchronize the data pulses between sender and receiver.
A "real-time clock," also called the "system clock," keeps track of the time of day and makes this data available to the software. A "timesharing clock" interrupts the CPU at regular intervals and allows the operating system to divide its time between active users and/or applications.
Dip switch on an old motherboard. Jumper pins with a cap on
COMTECH Page 25 of 55 Pages DIP (Dual In-line Package) switches are small electronic switches found on the circuit board that can be turned on or off just like a normal switch. They are very small and so are usually flipped with a pointed object such as a screwdriver, bent paper clip or pen top. Care should be taken when cleaning near DIP switches as some solvents may destroy them.
Jumper pins
Jumpers are small pins on the board with plastic or metal devices that go over the pins. This device is called a bridge or a jumper cap. When the bridge is connected to any two pins via a shorting link, it completes the circuit and a certain
configuration has been achieved.
Jumper cap
A metal bridge that closes an electrical circuit. Typically, a jumper consists of a plastic plug that fits over a pair of protruding pins. Jumpers are sometimes used to configure expansion boards. By placing a jumper plug over a different set of pins, you can change a board's parameters.
Modern motherboards come with the following features:
Processor slot : Processor slot is used for processor.
Memory banks : Memory banks are used for RAM modules.
AGP slot : AGP slots are used for graphics accelerators.
PCI slots : PCI slots are used to provide connectivity for PCI cards such as modems and sound cards.
IDE : IDE are used to connect and control IDE devices such as hard drives and CD-ROM drives.
USB ports : USB ports are used to connect USB devices.
These are just some of the features that a motherboard may have as standard, some motherboards come with integrated components such as a sound card, graphics card, modem, NIC (Network Interface Card) and more.
Types of Motherboards
The type of motherboards depends on the CPU it was designed for. You can therefore categories motherboards by which socket type they have. e.g. Socket A, Socket 478 etc.
The Type of motherboard you buy is very important, as it will need to house your CPU, and they are not interchangeable. When buying a motherboard, it will always tell you what socket type it has.
COMTECH Page 26 of 55 Pages
Chapter 3.2: How to Choose a Motherboard
As everything you have on the PC at some point needs the motherboard, you need to consider these components when buying a motherboard. For example, if you have a lot of devices with a PCI interface that you wish to use, there is little point buying a motherboard that only offers you 3 PCI slots. Like wise with memory, you have to make sure that there are enough slots for the amount of memory you have or wish to have.
The motherboard also needs the correct type of interface for your Memory, Graphics card, Hard disks and other items as well. You will find that most motherboards offer everything you need however it needs checking on when buying. Its especially important to pay detail to your motherboard if you want to use older components, which a new motherboard may or may not support.
The major difference between motherboards that support the same CPU is the model of the chipset (more on the chipset later). Different chipsets offer different performance and different features in terms of memory support, AGP port speed, Multiplier numbers, Bus speeds and much more.
When you are choosing one motherboard you have to consider: What's Your Processor?
First and most important thing to consider when buying your motherboard - what CPU or processor are you using? Motherboards are made differently, not all motherboards will support all CPUs.
What CPU you select will determine the type of motherboard you get. For example, if you want to use an Intel Pentium 4 CPU, the motherboard you select must be able to support that brand and model of CPU.
The motherboards are also designed to support specific speeds for a CPU, so make sure it can support the speed of the processor as well.
Choose Your Chipset
What is a chipset? Well, chipsets are the main controllers on the motherboard - they allow the CPU to interface with the various components and expansion cards installed.
When choosing your chipset, always bear in mind the type of memory supported by the motherboard. Make sure that the board supports the type and amount of RAM you need. Generally, choosing a chipset that supports high speed memory will allow your system to perform better.
COMTECH Page 27 of 55 Pages
What is a Motherboard Chipset?
A motherboard chipset controls all the data that flows through the data channels (buses) of the motherboard. The primary function of the motherboard chipset is to direct this data to the correct area's of the motherboard, and therefore the correct components.
Expansions Slots and Connectors
If you intend to various peripherals to the computer, then the number and type of expansion slots and connectors is important. By default, most motherboards these days have USB 2.0 ports incorporated into their design.
If you intend to buy expansion cards, make sure the board comes with an ample number of PCI slots.
Other Features
These days, most motherboards have a whole host of extra features loaded into them. These can include things such as on-board VGA, audio, a RAID controller, Modem or Network Card.
CHAPTER 4: RAM
RAM (Random Access Memory) is the basic working memory of your computer system. A computer used
RAM to hold volatile (Temporary) instructions and data needed for processing. Volatile simply means that it is
not permanent, which means anything written to RAM will be loses if the machine loses power or if it's turned off.
Another key point about RAM is that data stored init can be accessed much more quickly than data retrieved from the hard disk. Theoretically data retrieved from RAM is accessed 100 to 300 times faster then the same information from a hard disk, optical drive, or a floppy.
Memory is measured in bytes, so you'll often encounter the terms megabyte (MB) and gigabyte (GB) in describing RAM sizes (a megabyte is a million bytes; a gigabyte, a billion). RAM is something that you do not want to skimp on. You can choose a slower processor, but with RAM you want as much as you can get.
Types of RAM: SDRAM DDR DDR2 DDR3
COMTECH Page 28 of 55 Pages
SDRAM
Almost all systems used to ship with 3.3 volt, 168-pin SDRAM DIMMs. SDRAM is not an extension of older EDO DRAM but a new type of DRAM altogether. SDRAM started out running at 66 MHz, while older fast page mode DRAM and EDO max out at 50 MHz. SDRAM is able to scale to 133 MHz (PC133) officially, and unofficially up to 180MHz or higher. As processors get faster, new generations of memory such as DDR and RDRAM are required to get proper performance.
DDR Memory (184-pin DIMMS)
These were introduced in 2002 to replace the earlier SDRAM format. To use this type of memory you need a 184-pin socket for the module to fit into.
DDR Memory is available in different speeds of PC2100, PC2700, PC3200 (DDR400), and PC4000 (DDR500). The modules can be used singly or how desired however you cannot mix different speeds together.
DDR2 Memory (240-pin DIMMS).
This format builds on the technology of DDR . This standard has more pins and
its main developments are the ability to run faster whilst consuming less power. To use DDR2 memory you need a 240-pin socket for the module to slot on your motherboard. DDR2 Memory is available in many different speeds including PC2-3200 (DDR2400), 4200 (DDR2533), and PC2-5300 (DDR-667).
The modules can be used singly or you can install different speeds of DDR2 memory together if your motherboard supports the faster speed however faster modules will perform at the lower speed.
COMTECH Page 29 of 55 Pages This may be worth considering if you want to run Dual-Channel memory where you must use the same speed and ideally matching pairs to ensure compatibility.
DDR3 Memory (240-pins)
THIS is the latest memory standard (2008 onwards) taking over from the previous DDR and DDR2 standards. Although DDR3 comes with 240-pins the same as DDR2 the notch is in a different place so people can not install the wrong type.
DDR3 is not backward compatible with DDR2 in addition to the notch the voltage runs at a lower 1.5V than DDR2 1.8V. DDR3 memory will not fit into a standard DDR2 DIMM socket or an earlier DDR memory socket.
To use DDR3 memory, your system motherboard must have 240-pin DIMM slots and a DDR3-enabled chipset.
CHAPTER 5: HARDDISK
The hard disk (or hard drive) is the permanent
storage area of your computer. It stores information
whether the computer is on or off. A hard drive is a mass storage device found in all PCs (with some exclusions) that is used to store permanent data such as the operating system, programs and user files.
The data on hard drives can be erased and/or overwritten, the hard drive is classed as a non-volatile storage device which means it doesn't require a constant power supply in order to retain the information stored on it (unlike RAM).
Inside every hard drive are small round disk-like objects made of either an aluminum/alloy or a glass/ceramic composite, these are called platters, each platter is coated with a special magnetic coating enabling them to store data magnetically. Hovering above these platters are read/write heads that transfer data to and from the platters.
Hard drives come with many different storage capacities, hard drive capacity is measured in bytes, with common capacities being stated in MB (Megabytes) and GB (Gigabytes).
COMTECH Page 30 of 55 Pages
Hard Drive RPM Speeds
You will often see hard drives advertised as being capable of a certain RPM (Revolutions Per Minute), this figure (as the name suggests) refers to how many times the spindle makes a complete 360? turn in any single minute. RPM values range from about 5,400RPM to 12,000RPM and above.
How to Choose a Hard Drive
When you are choosi ng one Hard Drive you have to consider:
ATA and SCSI
In the hard drive world, there are two data access standards, ATA and SCSI (pronounced 'Scar-Zee'). Most of normal hard drives we're used to rely on the PATA standard. Some newer hard drives use the SATA standard.
SATA allows transfer speeds of up to 150 MBs while PATA gives up to 133 MBs. However, to use SATA, you'll need a Serial ATA controller, a SATA drive and a SATA power cable. The speed difference between PATA and SATA is also not significant unless you have a high-end SATA drive.
The SCSI standard is a very fast hard drive standard used for professional computer systems which demand extremely fast data access. SCSI drives provide an access time of about 9.5ms - which I feel is really not needed for average home use.
Disk Space vs. Price
An important factor to consider is the disk space versus price ratio. When you look at the 30 GB, 40 GB and 80 GBPATA hard drives, you'll find they are very close in price. For the average home user, however, 40 GB to 80 GB of disk space is plenty.
Drive Speed
If data access speed is important to you, you can go for faster SATA drives or SCSI drives. But remember that these drives come at a price premium and may not be necessary for average home use.
CHAPTER 6: CARD
6.1: Video Card
VGA Card is the one sending the monitor signal to the monitor.
A computer video card is placed in the motherboard, where it transfers video signals through a cable to your monitor. The video card can either be built into
COMTECH Page 31 of 55 Pages the motherboard or be a separate card that is placed in either the AGP or PCI-Express Slot.
The computer graphics
cards major job in a computer is to convert graphic patterns into signals for the monitor's screen. However in recent
times as the graphics card
has become more
advanced it has taken some of the jobs previously assigned with the CPU and through a graphics pipeline adds 2D and 3D effects and it also adds textures.
How to Choose a Video Card
The VGA Card price will change on
1. VGA Card Processor 2. VGA Card Ram capacity 3. Ram type of VGA Card
When you are choosing one Video Card you have to consider:
The best way to see what video card to buy is to consider how you're using your computer now. There are several categories:
Server
If you're using your computer as a mail server, FTP server, print server, or even a game server, you definitely do not need a high-end video card. What you need is a simple, no-frills low-end video card.
Simple Applications
Say you're using the PC for simple applications only, for example, word processing, email or web surfing. Again, you do not need the best video card out there. A cheap and decent one will do the trick.
Complex Applications
If you need to perform more complex tasks like 3D computer aided design or video editing, it will make more sense to go for a heavy duty card. Screen
COMTECH Page 32 of 55 Pages resolution and image quality tend to be important factors for this type of work. Look for a video card whose processor which supports a high screen resolution, with ample graphics memory.
General Games
If you'll only play simple games like Minesweeper, Reverse or Backgammon, then my advice is to save your money and just get a simple video card. No need for the latest 3D graphics gizmo.
6.2: Sound Card
Sound Card
The sound card is an essential component in the PC, since it translates digital
signals into analog audio for your listening pleasure. Well,
that's true, if you want to play games or run multimedia applications in your PC. Otherwise, it may not be necessary, especially in business environments.
Sound card ports
COMTECH Page 33 of 55 Pages A computer sound card is used by a computer for music, sounds during applications and entertainment (TV, movies and games). A typical sound card usually has four ports. The largest port is the Midi/Game port , which is used for connecting a joystick or gaming controller to. The other three ports look similar and are generally green, pink and blue.
Underneath each port will be a small engraving of what each port does. The pink
port is for a microphone which can record sound to the computer. The green port
is line out and this is where the speakers are connected to produce sound from the computer. The blue port is line in and this is for connecting a CD-player or cassette tape to the computer.
Remember a sound card by itself is not enough to hear sound. You will still need to purchase some computer speakers or a headphone set. If you want to make use of the microphone feature then you will need to buy a computer microphone and you should then be able to record sound to your computer.
How to Choose a Sound Card
When you are choosi ng one Sound Card you have to consider:
First thing to consider here is your intended usage of the sound card. If all you want is basic sound support and not spectacular 3D surround sound, I'd say go buy a cheap, simple card or even rely on your motherboard's on-board sound.
If you want great surround sound and better speaker connectivity options,
then you'll want to consider a dedicated sound card.
6.3: Modem Card
A device that translates data from your PC into a form that can be sent to other
COMTECH Page 34 of 55 Pages computers and converts it into something your computer can understand. A modem is the device most home computers use to connect to the Internet.
A Modem converts digital information into sound so that it may be transmitted over telephone lines. When the modem hears this sound on the other end it converts the sound back into digital information.
There are two types of modems: • INTERNAL
• EXTERNAL
External modems are slightly more expensive than internal modems and are housed in an external box or enclosure. External modems require a socket on the computer or port (usually the serial port on the back of your computer.) The serial port is also called a COM port, com for communications.
6.4: Network Card
A network interface card , more
commonly referred to as a NIC, is a device
that allows computers to be joined together in a LAN, or local area network. Networked
computers communicate with each other using a given protocol or agreed-upon language for transmitting data packets between the different machines, known as nodes . The network interface card acts as the liaison for the machine to both send and receive data on the LAN.
The most common language or protocol for LANs is Ethernet, sometimes referred to as IEEE 802.3. A lesser-used protocol is Token Ring. When building a LAN, a network interface card must be installed in each computer on the network and all NICs in the network must be of the same architecture. For example, all must either be Ethernet cards, Token Ring cards, or an alternate technology.
An Ethernet network interface card is installed in an available slot inside the computer. The NIC assigns a unique address called a MAC (media access control) to the machine. The MACs on the network are used to direct traffic between the
COMTECH Page 35 of 55 pages computers. The back plate of the network interface card features a port that looks similar to a phone jack, but is slightly larger. This port accommodates an Ethernet cable, which resembles a thicker version of a standard telephone line. Ethernet cable must run from each network interface card to a central hub or switch. The hub or switch acts like a relay, passing information between computers using the MAC addresses and allowing resources like printers and scanners to be shared along with data.
A network interface card does not have to be hard wired with physical cable. Wireless Ethernet cards are installed like their wired counterparts, but rather than a port for an Ethernet cable, the card features a small antenna. The card communicates with the central wireless switch or hub via radio waves. Wireless LANs may have some restrictions depending on the material the building is made from. For example, lead in walls can block signals between the network interface card and hub or switch.
When buying components for a LAN, make sure the NICs and hub or switch have the same capabilities. The entire network must be either wired or wireless, so a wireless network interface card cannot talk to a wired switch or hub. In addition, newer versions of hardware will likely support more features and/or greater speeds than older versions. Make sure your central switch or hub can utilize the highest capabilities of the network interface card under consideration.
CHAPTER 7: PERIPHERALS
Chapter 7.1: Keyboard and Mouse
These two input devices are obviously needed, otherwise you can't interact with the computer system. These components are fairly standard stuff and can be purchased at pretty cheap prices.
Keyboards
The keyboard is the main input device for most
computers. There are many sets of keys on a
typical “windows” keyboard. On the left side of the
keyboard are regular alphanumeric and
punctuation keys similar to those on a typewriter. These are used to input textual information to the PC.
A numeric keypad on the right is similar to that of an adding machine or calculator. Keys that are used for cursor control and navigation are located in the
COMTECH Page 36 of 55 pages middle. Keys that are used for special functions are located along the top of the keyboard and along the bottom section of the alphanumeric keys.
Keyboards are mainly divided into two types
1.Multimediakeyboard. 2.OrdinaryKeyboard.
Mouse
Mouse is another input device used in computer. Mouse is a device that controls the movement of the cursor or
pointer on a display screen.
A mouse is a small object you can roll along a hard, flat surface. Its name is derived from its shape, which looks a bit like a mouse, its connecting wire that one can imagine to be the mouse's tail, and the fact that one must make it scurry along a surface. As you move the mouse, the pointer on the display screen moves in the same direction.
Mouse contain at least one button and sometimes as many as three, which have different functions depending on what program is running. Some newer mouse also includes a scroll wheel for scrolling through long documents.
Chapter 7.2: Floppy Drive and CD-Rom
Floppy Drive
A 3.5” square holding a flexible magnetic disc that holds information or data. You need a floppy drive to read the floppy. A floppy disk can hold only 1.44 megabytes, but it is portable and allows you to make copies of your files.
CD-Rom
A CD-ROM drive used to be an 'optional extra' in computers - it is no longer so. Most software packages come in CD format, so you must have a CD-ROM drive to read them. Typically, CD-ROM drives today need to be at least 24X speed to keep up with the newer software applications out there.
COMTECH Page 37 of 55 pages A CD drive connects to the computer motherboard through two types of cables.
The older and more common connection is through the IDE Ribbon cable .
Recently SATA (Serial ATA) drives have been produced and will gradually become more common. The benefits of having SATA cables is that they are smaller and the transfer rate is higher.
Floppy drives were the main source of data transfer and files were small enough to fit on them. However, today even CD drives are getting out of date and are fast being replaced by the DVD ROM and DVD RW Drives.
CD-RW
CD writer is used to write CD. It can also used as a CD drive. CD can be able to write with different formats. By using CD writer we can able to write with different speeds. There are different types of writers are available in the market with different writing speeds.
On a CD drive there is usually some numbers with a x symbol after it. This stands for times, for example common speeds are 4x, 8x, 16x, 18x, 24x, 32x, 40x and 52x. CD RW drives have speeds like 24x-10x-40x or 52x-32x-52x.
How to Choose a CD-RW
When you are choosing one CD-RW you have to consider:
Drive Speed
For CD writers, you should generally look for a 40X record speed or faster. If you buy anything that is slower, it will definitely waste a lot of time when you're burning CDs.
Chapter 7.3: Monitor
Monitor
Monitor is the display device. Many
times per second, the video card sends signals out to the monitor. The
information video card sends controls which dots are lit up and how bright they are, which determines the picture you see.