How to Change a Computer Power Supply
Running a PC with power supply fan problems will cook the machine, so if you don’t hear a fan running or hear one starting to die, the only thing to do is to shut down the system. Then head for the computer store and buy a new power supply. They come very cheap these days.
Changing a computer power supply can be done by just about anyone who can operate a screwdriver. Pay attention to the box label, because the only difference in appearance between an AT supply box and an ATX supply box will often be that single letter. Here’s how to change a computer power supply:
1. Unplug the computer.
2. Spend a minute studying what cables go where, including disk drive data cables you might dislodge when untangling the existing power cables.
3. Disconnect the 2-inch wide cable that goes to the motherboard. These have a clip that must be depressed before you can remove them. Then disconnect the power supplies to your various disk drives.
4. Holding the power supply with one hand, remove the four screws that attached it to the case with the other hand. (Motherboards get cranky when heavy metal objects fall on them.)
5. Attach the new power supply and connect the cable to motherboard and disk drive. It takes about 10 minutes.