Your PC s System UnitThe Mother Ship

Your PC's System Unit The Mother Ship

The most important piece of hardware in your computer system is the system unit. This is the big ugly box that houses your disk drives and many other components.

note

Desktop computer systems have separate system units, monitors, keyboards, and mice; portable PCs have all their components crammed into a single, lightweight case which makes them much harder to upgrade!

You should keep your system unit in a well-ventilated location free of excess dust and smoke. (The moving parts in your computer don't like dust and dirt or any other such contaminants that can muck up the way they work.) Because your computer generates heat when it operates, you must leave enough room around the system unit for the heat to dissipate. Never place your computer in a confined, poorly ventilated space; your PC might overheat and shut down (or even damage critical internal components) if it isn't sufficiently ventilated.

For extra protection for your computer, connect the power cable on your system unit to a surge suppressor rather than directly into an electrical outlet. A surge suppressor which looks like a power strip with multiple outlets protects your PC from power line surges that could damage its delicate internal parts. When a power surge temporarily spikes your line voltage (causes the voltage to momentarily increase above normal levels), a surge suppressor shuts down power to your system, acting like a circuit breaker or fuse.

tip

Although a surge suppressor will protect your system from electrical spikes, you'll still lose any data you were working on if your power goes out. If you use your PC for applications in which you can't afford even a momentary shutdown, you should invest in a battery-operated backup power supply (also called an uninterruptible power supply, or UPS). These devices send auxiliary power to your PC during power outages and provide "clean" power in areas where power line spikes and brownouts are common.

The back of the system unit typically is covered with all types of connectors. This is because all the other parts of your computer system connect to your system unit, and they all have to have a place to plug in. And, because each component has its own unique type of connector, you end up with the assortment of jacks (called ports in the computer world) that you see in Figure 1.2. The back of your PC might look somewhat different than the one pictured here, depending on the manufacturer, but this should help you identify the major connectors.

Figure 1.2. The back of a typical system unit just look at all those different connectors!

The cables that connect your peripherals to your system unit can be a source of trouble if they're not connected correctly. Make sure that you plug all cables securely into their sockets; in fact, screw them into place if you can. Make certain, too, that the cables don't have abrupt bends or kinks in them. If your cables aren't as straight as possible, the wires inside them might break or become damaged.