Lifehacker reader Jenny writes in with a fix to an audio equipment problem that sounds like it came from the "Hit It Really Hard" repair theory, but comes endorsed by at least a few other audiophiles I found in a bit of Google-ing. Both her old record-player and a newer CD player were causing a loud crackling noise whenever she adjusted the volume knob. One solution she found—take the device apart and clean the knob contacts—wasn't all that appealing, so she tried another
Turn the stereo off, then quickly turn the volume knob back and forth for about a minute to get rid of most of the grime that is causing the static. Then turn it back on.
You wouldn't want to do this too quickly, of course, but it's not a bad idea for older equipment you want to hold onto. Another sage suggestion I found was using a low-powered, hand-held vacuum cleaner to suck out any particles that could be causing the same problems.