Dealing with a Computer's Noisy Power Supply


The noise that can come from your computer's power supply can sound like either a purr or wailing. The noise comes from the fan inside the power supply that blows air across the power supply's innards. The fan cools off the inside of your computer at the same time.

If your power supply is really loud, there's just no getting around the racket without buying a new one that's designed to run less noisily.

Consider the following:

If your power supply is much too noisy, think about replacing it. Today's power supplies are much quieter than the rumblers released five or more years ago.
If your power supply doesn't make any noise, you're in even worse trouble. Hold your hand near the fan hole in the back. If you don't feel any air blowing out, the fan has died, and your computer is getting hotter by the second. Save your work quickly and immediately turn off your computer. Buy a new power supply before turning on your computer again. Without a power supply's cooling fan, a computer can overheat like a car in the desert with an empty radiator.
Don't try taking apart your power supply to quiet down the fan or make repairs. Power supplies soak up electricity and can zap you, even when they're unplugged. Never mess around inside a power supply.


Sometimes it's hard to differentiate between a noisy power supply fan and a noisy hard drive. Each has a constantly spinning motor, so both are susceptible to the burned-out bearing syndrome.

To tell whether the noise is coming from your power supply or your hard drive, turn off your computer, unplug it, and open the case. Then pull the power supply's cable out from the back of your hard drive. Plug your computer back in and turn it on. Because the hard drive isn't getting power, it doesn't turn on with the rest of your computer. If you hear a noise, it's your power supply.

If you don't hear a noise, it's your hard drive. Unfortunately, hard drives cost much more to replace.