Components of a computer: Hardware

Unit 1: Deals with Fundamental of Hardware and Software.

At the end of this section you should know what is a computer and the function and the basic components of all computers.

Hope you will have fun in this section:

1. Getting to know the basics of computers

http://www.gcflearnfree.org/computerbasics/1.2

http://www.freefunfolder.com/documents/PartsoftheComputerHARDWARE.pdf

Fundamentals of Hardware and Software

A Computer is an electronic device, operating under the control of instructions stored in its memory. It can:

• accept data (input)
• manipulate data (processing)
• produce results (output) from the processing
• store the data and results for future use (storage)

Components of a Computer

The basic components of a computer are hardware and software.

Hardware

This is the name given to the physical parts of a computer. There are five general categories:

System unit

The system unit is the core of a computer system. Usually it's a rectangular box placed on or underneath your desk. Inside this box are many electronic components that process information. The most important of these components is the central processing unit (CPU), or microprocessor, which acts as the "brain" of your computer. Another component is random access memory (RAM), which temporarily stores information that the CPU uses while the computer is on. The information stored in RAM is erased when the computer is turned off. Almost every other part of your computer connects to the system unit using cables. The cables plug into specific ports (openings), typically on the back of the system unit. Hardware that is not part of the system unit is sometimes called a peripheral device or device.

System unit

Storage

Your computer has one or more disk drives—devices that store information on a metal or plastic disk. The disk preserves the information even when your computer is turned off.

Hard disk drive

Your computer's hard disk drive stores information on a hard disk—a rigid platter or stack of platters with a magnetic surface. Because hard disks can hold massive amounts of information, they usually serve as your computer's primary means of storage, holding almost all of your programs and files. The hard disk drive is normally located inside the system unit.

Hard disk drive

CD and DVD drives

Nearly all computers today come equipped with a CD or DVD drive, usually located on the front of the system unit. CD drives use lasers to read (retrieve) data from a CD; many CD drives can also write (record) data onto CDs. If you have a recordable disk drive, you can store copies of your files on blank CDs. You can also use a CD drive to play music CDs on your computer.

CD

DVD drives can do everything that CD drives can, plus read DVDs. If you have a DVD drive, you can watch movies on your computer. Many DVD drives can record data onto blank DVDs.

Tip

• If you have a recordable CD or DVD drive, periodically back up (copy) your important files to CDs or DVDs. That way, if your hard disk ever fails, you won't lose your data.

Floppy disk drive

Floppy disk drives store information on floppy disks, also called floppies or diskettes. Compared to CDs and DVDs, floppy disks can store only a small amount of data. They also retrieve information more slowly and are more prone to damage. For these reasons, floppy disk drives are less popular than they used to be, although some computers still include them.

Floppy disk

Why are these disks called "floppy" disks? The outside is made of hard plastic, but that's just the sleeve. The disk inside is made of a thin, flexible vinyl material.

Mouse

A mouse is a small device used to point to and select items on your computer screen. Although mice come in many shapes, the typical mouse does look a bit like an actual mouse. It's small, oblong, and connected to the system unit by a long wire that resembles a tail. Some newer mice are wireless.

Mouse

A mouse usually has two buttons: A primary button (usually the left button) and a secondary button. Many mice also have a wheel between the two buttons, which allows you to scroll smoothly through screens of information.

Mouse pointers

When you move the mouse with your hand, a pointer on your screen moves in the same direction. (The pointer's appearance might change depending on where it's positioned on your screen.) When you want to select an item, you point to the item and then click (press and release) the primary button. Pointing and clicking with your mouse is the main way to interact with your computer.

Keyboard

A keyboard is used mainly for typing text into your computer. Like the keyboard on a typewriter, it has keys for letters and numbers, but it also has special keys:

• The function keys, found on the top row, perform different functions depending on where they are used.
• The numeric keypad, located on the right side of most keyboards, allows you to enter numbers quickly.
• The navigation keys, such as the arrow keys, allow you to move your position within a document or webpage.

Keyboard

You can also use your keyboard to perform many of the same tasks you can perform with a mouse. For more information, see Using your keyboard.

Monitor

A monitor displays information in visual form, using text and graphics. The portion of the monitor that displays the information is called the screen. Like a television screen, a computer screen can show still or moving pictures. There are two basic types of monitors: CRT (cathode ray tube) monitors and the newer LCD (liquid crystal display) monitors. Both types produce sharp images, but LCD monitors have the advantage of being much thinner and lighter.

LCD monitor (left); CRT monitor (right)

Printer

A printer transfers data from a computer onto paper. You don't need a printer to use your computer, but having one allows you to print e‑mail, cards, invitations, announcements, and other material. Many people also like being able to print their own photos at home. The two main types of printers are inkjet printers and laser printers. Inkjet printers are the most popular printers for the home. They can print in black and white or in full color and can produce high-quality photographs when used with special paper. Laser printers are faster and generally better able to handle heavy use.

Inkjet printer (left); laser printer (right)

Speakers

Speakers are used to play sound. They can be built into the system unit or connected with cables. Speakers allow you to listen to music and hear sound effects from your computer.

Computer speakers

Modem

To connect your computer to the Internet, you need a modem. A modem is a device that sends and receives computer information over a telephone line or high-speed cable. Modems are sometimes built into the system unit, but higher-speed modems are usually separate components.

Cable modem

Source cited:

http://windows.microsoft.com/en-us/windows/computer-parts#1TC=windows-7

 

Common Computer Hardware Problems

when using a computer, a number of simple problems can occur and there are checks which you can do to identify the possible cause(s). By performing a series of checks, you can decide whether the problem can be corrected immediately or if you need to seek further technical assistance.

Computer does not respond when power is turned on

• Make sure the power cable is connected to the power connector on the back of the computer and plugged into the electrical outlet.
• If the computer is plugged into a power strip or surge suppressor, ensure that the power strip is connected to an outlet and turned on.
• Check that the electrical outlet is working. You can do this by testing it with another device such as a lamp.
• Briefly bypass in turn the surge suppressors, power strips and extension cables that connect the computer directly to the power outlets, to see if the computer turns on.

Common PC hardware and the solutions
Computer Freeze
Heat is the measure Reason for PC hardware problems. Ensure if it’s computer freeze or lockup. Generally, your computer temperature is controlled by the internal fan called the Heat Sink. Dust is another enemy of PC hardware as it sticks on motherboard and electrical components. You can control overheating by removing dust from around the internal fan.


System Error Blue Screen
Often it is seen that a blue screen appears suddenly while you are working or when you start your computer. This is usually due to either a hardware failure or a driver problem. Reinstalling the driver or correcting the hardware problem can help to solve the issue. If nothing seems to work, you should consider backing up and re-formatting your Hard Drive, then reinstalling your operating system.

RAM Faults and Errors
Whenever RAM fault occurs your monitor shows a blue screen with a memory reference like x000xxxx as a boot interruption. RAM faults cannot be prevented but you can fix them. There may be frequent PC restarts. This is due to faulty RAM chips. These Faulty RAM chips are unable to store the boot loader or NT loader file therefore the OS cannot find it and hence it shuts down all the processes, due to non-availability of the boot loader file in the RAM as a result the PC restarts again and again.
This problem can be fixed by replacing the old RAM with a new one. You must know the model compatibility of you motherboard before buying a new RAM. It may be DDR, DDR2 or DDR3. Just do it!


Laptop’s dead
The laptop does not turn on at all no matter what you do. There are several possible scenarios that may lead to this outcome including the battery draining completely because of a malfunctioning AC adapter. Maybe the DC jack has to be replaced because it makes no contact with the motherboard. The worst scenario by far is the one with the failed motherboard. If that is the case, just go and buy yourself a new laptop.

Noisy Computer
It means that the computer system is making noise while running. The reason of Noisy Computer is Dirty Fan. The dust particles sticks on the Fan including the Heat Sink and other parts such as Motherboard and other electrical parts of computer .This dust Blocks the smooth action of Fan and causing the fan to make noise.
Clean your system completely by removing motherboard from its place and also clean the Fan and Heat sink with a brush or soft cloth.



Liquid spilled on laptop
For some careless guys, it’s easy to spill something on the laptop and it’s stopped working. Liquid spills are very dangerous and unpredictable. If it happened, turn off the laptop ASAP, remove the battery and do not use it until all internal parts are inspected for liquid damage. It’s still possible the laptop will work again after you clean the damage.


Printer problems

• Ensure the printer driver is installed on the computer.
• Ensure that the printer is plugged into a power strip or outlet and the printer is turned on.

Printer is receiving power but is not printing correctly

• Check that the printer contains one or more ink cartridges, depending on the type of printer. These should be correctly installed in the printer. Refer to the printer manual for the installation instructions for the ink cartridges.
• If the print quality is poor, the ink cartridge or print head may need to be cleaned. Follow the printer user guide instructions. Alternatively, the print cartridges may need to be replaced.
• Check that the printer settings for ink cartridge alignment, paper orientation and margins are correctly set.
• If the print quality is low, check the print quality you are using. Draft, Normal and Best are example of print quality options you may see for an ink-jet printer.

If no paper is seen when you try to print

• Make sure that no parts of the printer are open.
• Check that the paper is correctly placed in the printer.
• Ensure that you are using the correct data cable, and that the cable is connected to the computer and the printer.
• Make sure you have selected the correct printer within the application you are using on the computer. Several printers may be installed and you must ensure that the required printer is selected in the wrong printer you may get an illegible printout of the data or none at all.

When all else fails
Turn your printer off and shut down the computer. turn the printer back on, then restart the computer. Sometimes rebooting can resolve certain computer problems.



Monitor problems

Blank screen

How to Fix a Blank Display Problem

When your computer does not display anything on the monitor you have a No Display or Blank Display problem. This can be caused by any of the following reasons:
· Monitor or System has no Power
· Monitor is defective
· Loose VGA/DVI Cable Connection
· Video Card Problem
· AGP/PCI-e Connector Problem / Motherboard
· System RAM Problem
Monitor or System has no Power
First thing is to check if the system powers up when pressing the power button, if not check cable connections and the power source. Next is to check if the monitor powers up when you press the power button. If not, check power cable and the power source for the monitor.
If this procedure solves the problem, there may be a loose connection in the power cables of the system or the monitor.
Monitor Is Defective/Loose VGA Cable Connection
After checking if the system and monitor have power and you still encounter the no display problem, try to swap monitors with another computer to check if the monitor is defective or not. You can also try to reinsert the VGA cable to the VGA port of your video card to see if the connection is loose or maybe the VGA cable of you monitor is defective.
Video Card Problem / AGP/PCI-e Connector Problem
After verifying that the monitor is working, the next step is to check the video card. Power down your computer and unplug power cables. Open your computer and try to reinsert the video card. After inserting the video card, power up the PC to check if this solves the problem.
If this does not solve the problem try replacing the video card. After replacing the video card, if you still experience the problem, your system board or agp/pci-e connector might be causing the problem. You correct this by replacing your motherboard.
System RAM Problem
No display problem can also be caused by the system RAM. When your system RAM is defective or is not properly inserted in the memory slot of the main board. the system may not boot. You can try to reinsert the RAM or replace it if it is defective.

Source Cited: http://www.online-tech-tips.com/computer-tips/blank-display/




Screen Difficult to read

• Monitor setting such as colour, contrast and brightness may need to be adjusted.
• Ensure that no strong sources of magnetism, such as speakers and amplifiers, are near the monitor.
• Keep monitors away from external power sources such as fans and fluorescent lamps and radios. These can cause the screen image to appear to vibrate. Nearby power sources should be turned off to check for interference.
• If monitor is facing a bright source of light such as windows or lights, the image may be difficult to see. The monitor should be turned away from strong light sources.

Reference and Further Reading

Gay, Glenda & Blades, Ronald (2005). Oxford Information Technology for CXC CSEC 'Common Computer Hardware Problem' (p.46 & 47).

Source cited: http://www.cisco1900router.com/how-to-solve-the-common-pc-hardware-software-problems.html