Through most of my articles, I’ve tried to explain just how easy it is to build a computer. But there is one chore harder than the rest, and it’s one that most people don’t give a thought to, until they are confronted by it. This is connecting the case wires to the motherboard.

When you open up a new PC case, you’ll see a group of candy striped wires lying in the bottom. These are the wires that lead to the reset switch, the LEDs for the power and the hard drive, and that annoying little system speaker that beeps at you when you make an error.

These wires plug in to a grid of pins usually located at the lower front corner of the motherboard. The trouble is, which wire goes to which pin?

Some boards have the pins marked with extremely small print, that a middle-aged fellow like myself requires a magnifying glass to read. Abbreviations used can vary. For instance, the hard drive LED may be marked “HD”, or it may be marked “IDE”. Also note that many of the wires come in pairs, with a positive and a negative wire. They must be turned the right way if they are to work.

It is best to consult the motherboard’s manual, if you have one. Here can be found a diagram showing you exactly which pin is which, and if there are “dead” pins not used on that particular model.

This is particularly helpful in hooking up the speaker wires. The plug for it will span four pins, with the speaker wire on one side, and a 5V hot wire on the other. The grid will probably have one pin marked “5V”, but bear in mind there’s nothing to keep you from turning the plug backwards, so be careful.

Michael Quarles is the author of Building a PC for Beginners.

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