Originally Posted by gorath23
You know what, I don't really know
, I guess its just all the wiring/shafts etc behind the knobs and same on the inside. I've never actually done it myself, I always take my amps to a tech to get them cleaned up. Less chance of death that way
There's usually some sort of hole in the potentiometers that you can spray contact cleaner into. Spray once, rock back and forth a couple of times, then spray once more (don't skimp on it this time) to flush all the crap out.
Anyway dirty pots should not have a huge effect on gain/distortion. The main problem i have when buying used gear from around the 80's-90's is the input jack, which is usually dirty as hell (and especially if it hasn't been used in a while).
To diagnose this try moving your plug around in the jack while playing to see if you can hear a difference, and, anyway, spray the jack hole full of cleaner in all directions (bend the nozzle inside), spray the jack plug, then plug it in, take it out, rotate it around, plug in / out etc and leave the plug in the jack
for an hour while the cleaner evaporates. Then do it one more time, this time more of a flush so spray plenty, then try playing it once it has dried out. Doesn't matter if you spill the cleaner all over the place or if it drips down from the jack or whatever, it dries out and leaves no trace (but it might clean affected areas so they might look different, but they're supposed to look like that).
Now if that doesn't fix it the jack might be loose, then you can bend the tip of the jack back in place to tighten it up. Works on closed jacks as well, just use a #0 flathead screwdriver or something similar to push the tip back in place through the small holes in the jack.