Diagnosing Funny Computer Noises

Reader Ray writes: I've noticed my computer making a scratching-skipping sound. In the past this sound preceded a hard drive replacement. Are there any diagnostic tests to check my hard drive?

Strange noises are the easiest way to tell if a computer is going south, especially the hard drive. But it's important not to panic and misdiagnose an odd noise as something more severe than it really is.

First, you need to rule out various other possible sources of the noise, specifically any moving parts in your machine that aren't the hard drive. Optical drives make a lot of noise that can be described as "scratching-skipping," so make sure there's no wayward disc left spinning in your DVD drive. Fans can also make noises like that. Get right next to the fans and listen closely to them; look for excessive debris clogging them or other obstructions. If you suspect a fan is making noise, try turning off the PC, inserting a pencil into the grille to keep it from spinning, then turning the PC back on. Don't run the PC for more than a minute like this, but that should be plenty of time to see if the fan is the source of the problem. (Naturally, cleaning out your PC will help if this is the issue.)

Final thing to check: The speaker. Almost every PC has a small built-in speaker in it, even if you use external speakers. These internal speakers are invariably cheap and subject to interference, especially if you have other electronics nearby.

Another good way to tell if the hard drive is the culprit: Lightly touch the top of it when you hear the noise. You should be able to feel vibrations and "grinding" to coincide with the sounds.

Now, what do you do if your hard drive is making more noise than normal? Frankly, I'd bypass the diagnostic software (which may say nothing is wrong at all) and replace the drive as soon as possible. Noisy hard drive means dying hard drive. Maybe not in the next hour, but probably within a matter of weeks. And severe noise like that could indicate data loss is already occurring. Back up your data immediately, even if you decide not to replace the drive until later.

For less severe problems, there are large number of utilities you can use to check a drive's health. They aren't perfect, but they're a good start. Check out the selection of tools on this page for starters, where you'll find a list of every hard drive manufacturer with links to their diagnostic tools. If your manufacturer is listed, give its tool a try. If not, try the Hitachi Drive Fitness Test, which works on most brands. For real-time monitoring in Windows, I've recommended S.M.A.R.T. Monitor in the past. (Scroll down that page to find the download link; more coverage of the software here.)