[Sndnerd]

I have a 24 channel D-command that I bought used and I have bad case of sticky faders. Here's what's going on: random faders on random given days don't register touch. If I cajole them enough, tap, wiggle, caress them.. they start to work again. Popping the caps is usually the first course of action. but sometimes that doesn't work. At first I thought I had dead faders.. bought 4 new ones from the avid dealer and they promptly stopped working. way to waste 500 bucks.. anyways I thought it might be a grounding issue- tried plugging into different circuits (that have different grounds) and same thing. I guess next step would be to get ground tested (not sure how to do this?) aside from that has anyone gone through this before? it's happens both equally in main unit and fader pack. It's driving me crazy.