Assembly

1. Assembly Computer Sytem

2. Choosing the parts • The first step to building a computer is acquiring the parts. • A computer is made up of a case, also called a chassis, which houses several internal components, and the external components, including peripherals.

3. Inside the case go the following internal parts: • Power Supply/PSU power supply unit, converts outlet power, which is alternating current (AC), to direct current (DC), which is what the internal components require, as well as providing appropriate voltages and currents for the various internal components. • Motherboard/Mainboard • Processor/CPU • RAM • Hard Drive/Hard Disk • Optical Drive • Video Card/Graphics Card/GPU • Keyboard • Mouse • Monitor

4. Handling and transportingequipment The delicate parts of a PC system are easily damaged by careless handling during installation, maintenance and transportation. The following tips on good handling methods should therefore be followed at all times: 1. When moving a computer and peripherals from one location to another, unplug all connectors and carry each item separately. Do not try and carry two items at once to save unplugging the joining lead, such as a monitor and base unit. If the computer system is to be moved over any great distance, place the monitor system unit and peripherals in their original packing.

5. Handling and transportingequipment 2. Hard drives are particularly delicate due to their delicate head mechanism. It is therefore essential to protect them from severe bumps and jolts. When transporting a hard drive, wrap it in an anti-static bag and place it in a box with plenty of shock absorbing material. 3. CD-ROMs and floppy drives are sometimes supplied with a head restraining device. Fit these back on the drive before they are transported (Figure 1).

6. Handling and transportingequipment

7. Handling and transportingequipment 4. New printers, scanners and other peripherals with moving parts are packed using some form of restraint to arrest the mechanism during transit. This varies from a special arresting mechanism to pieces of foam. The restraints must be removed before use and refitted when the equipment is being transported over any great distance. For items with a Return to Supplier Warranty, keep the original packaging for the duration of the warranty period, in case they need to be returned for replacement or repair.

8. Transporting potentially dangerous equipment Monitors and laser printers have circuits that operate at several thousand volts. When moving these devices, it is important to allow time for the internal voltages to decay to a safe value prior to transportation. For example: a monitor that has been abruptly disconnected from the mains, could hold an electrical charge of several thousand volts. This happens because the internal high voltage circuits have not had sufficient time to discharge to earth via the mains socket. A person carrying the monitor could therefore receive a sudden electric shock, as the high voltage finds another convenient path to earth through his or her body.

9. Transporting potentially dangerous equipment directly harmful, the sudden jolt of the shock could cause the monitor to be dropped, resulting in possible CRT implosion and injury.

10. Here is the correct way to disconnect all mains operated peripherals: • After closing down the operating system (OS), switch off the power to the computer and peripheral at the mains socket but keep the power leads plugged in to allow any built up charge to dissipate safely to earth through the earth pins of the mains plug and socket. • Wait at least 30s to allow high voltages to discharge to earth. • Now disconnect the signal cables first followed by the power • leads. This prevents any remnant static charge from dissipating through the computer input/output (I/O) ports. Carrying out this simple procedure will prevent accidents due to electric shock. It will also eliminate the chance of damaging the associated I/O circuitry when the device is removed. One of the biggest causes of damaged adapter cards, motherboards and peripheral devices, is careless handling – particularly during connection and disconnection.

11. Static sensitive devices • Most integrated circuits used in a modern computer system are fabricated using complementary metal oxide semiconductor (CMOS) technology. • E.g. CPU or RAM device • These devices are very easily damaged by static electricity picked up on our bodies going about our normal daily life. • Some technicians who should know better, are very blasé about static electricity precautions. They often come out with comments like, ‘I never wear a wrist band and I’ve never had a device failure’. The point they are missing is that static damage does not always show up immediately, it could take a month or so before a damaged device finally fails.

12. Preventing static damage • When inserting or extracting printed circuit boards, or handling disk drives and ICs, always wear an earthed anti-static wrist band. An earthed wrist band removes the static from your body and clothes. Adapter cards, memory modules, CPUs and drives, often cost several hundred pounds each, so it is foolhardy to risk damaging them for the sake of a wrist band that costs just a few pounds. • Try not to touch the ICs and tracks on adapter cards. Handle all cards by their edges only. Keep all adapter cards and ICs away from monitors and laser printers. The high static charges present on these units can easily cause static damage. • Always store unused adapter cards, disk drives, memory devices and other static sensitive devices in their anti-static bags. Only remove them from the bag when you are ready to use them and wear an earthed wrist band. • Disregard and put down to ignorance, the often quoted phrase from some complacent members of the PC fraternity, ‘I never wear a wrist band…’What happens to a static damaged card, weeks or months later, they would never think of putting down to their own former careless handling methods

13. Preventing static damage

14. Choosing the parts These are the parts that a standard PC will use. We are not considering such as touch screen, or voice-controlled systems. You might want to make a check list (perhaps using a spreadsheet) of parts to use as you go about your process of research and selection. That way you wont find yourself sitting down with a pile of brand new hardware only to find that you forgot an essential component.

15. There are three important questions you should answer which will guide your purchases: • What will be the main function of the computer? • What useful parts do you have on hand, from an old computer or otherwise? • How much can you afford to spend on the system?

16. What operating system am I going to use? • Before you buy components, be sure that they are supported by the operating system you plan to use. Almost all current, commonly available PC devices have drivers available for current versions of Windows (generally, anything 2000, XP, Vista, or newer)

17. What will be the main function of the computer? • If you’re going to build a computer from scratch for a specific purpose, you’ll want to keep that purpose in mind when choosing your components; don’t just go to the store or an online shop and start buying. Consider what you want to use the computer for, you may be able to save money by specifying expensive, premium parts only where needed.

18. Simple web surfer To provide basic functionality to a user who just needs web surfing, a little word processing, and the occasional game of solitaire, its important not to go overboard. Such a user has no need for a top of the line processor or 3D graphics card. • low-level processor • enough RAM for the OS • mother board with built in Ethernet, video and audio

19. Gaming system Were talking about cutting edge 3D gaming first-person shooters or real-time strategy games with thousands of troops on the screen at the same time, with anisotropic filtering and anti-aliasing and mip-mapped specularreflections and a lot of other confusing terminology that describes visual effects designed to make your system fall down on its knees and cry like a little girl. • fastest processor you can afford • plenty of RAM well as a motherboard to match, since the speed of the motherboard buses can limit high-end components.

20. But even that won’t be enough, so youll need to offload as much of the work from the processor as you can. • The first way you can do this is by adding a video card. • Sound card

21. Office computer An office computer can be expected to do word processing, spreadsheet and database work, internet and intranet access (including e-mail) and a little light development of spreadsheets, databases, and presentations. It might also be called on to do page layout work, some 2D graphic creation, and/or terminal emulation. • strong mid-level processor, processor one or two places from the top of the line(Intel Core 2 Duo 6600 or 6700) • Plenty of RAM will also facilitate multitasking and save time.