Internal Conductors (Wires)

Remember that internal connector receptacles and plugs are keyed for each other; or in some cases, they will have guide pins. The receptacle and the plug must match to be connected properly. Pay attention to this because you can cause extensive damage if the connection is reversed or if you force the connection. Also, remember that connections should be made with the power secured to the computer. INTERNAL CONDUCTORS (WIRES).— The wires will take individual signals or mass data and route them for distribution throughout the computer. Signal names used by a computer can be found in the wire listings, computer prints, or the description of each pcb. Learn to interpret the computer’s wire listings and prints. This skill will prove invaluable when you have to trace signals from point to point when diagnostic testing does not prove conclusive in finding malfunctions. To find information on how to interpret signals and signal distribution, look in the computer’s technical manuals. The wires can be connected between two plugs, between two receptacles, between a receptacle and a plug or vise versa, or they can originate and terminate on the same receptacle, plug, or indicator/switch. They are used in every part of the computer and any type of computer. The following are some examples of where conductors are terminated: Wiring harness plugs connector receptacles of a modular frame or cabinet Between a connector receptacle and a plug inside — — a module l Connector receptacles inside a chassis-, assembly-, rack-, or cage-designed frame or cabinet Q Connector receptacles of a motherboard or backplane l Indicators and switches throughout the computer . External connector receptacles Conductors used internally in a computer are insulated with a plastic coating. Be careful when making repairs. If the repair calls for soldering, the fumes from heating the plastic coating can be toxic. Remember, conductors can originate and/or terminate from or to the same connector receptacle, indicator, or switch. Because wiring must be neatly organized, wire bundles in computers are used to route the conductors from point to point. The wire bundling method of organizing the wires is used for interconnections inside of a module, in a cage or rack, in a chassis or assembly, and inside a frame or cabinet. The wire bundles are secured by either lacing, spot tying, or self-clinching cable straps. The conductors are arranged in what is called a wiring harness. The wiring harness may include terminations. A wiring harness allows the wires to be neatly organized and uses the limited space more effective] y. Figure 2-25 shows a wiring harness used inside a computer’s cabinet to secure the conductors in bundles. Notice how the wire bundles of the wiring harness are secured to keep the wiring neatly organized. Figure 2-26 is an example of a wiring harness connector (rectangular) assembly. Notice the plug and the connector pins (electrical contact). The plug is used to Figure 2-25.—Example of wire bundling inside a computer’s cabinet using a wiring harness. 2-20