For all of the potentiometers that you can get to without disassembling the amp, put a couple of drops on the top of the pot and move the knob around to get the cleaner to flow between the segments. Then rotate them back and forth to try to clean them if dirty. Clean all of the rest of the switches.
Are all of the contacts in the telco-jack on the front of the amp straight? None shorting together?
Are all of the contacts in the telco-jack on the front of the amp straight? None shorting together?
I will check these things as soon as I have time. If I don't find anything I think I will throw in the towel. The headunit I'm buying has a built in LP filter, and I'd rather not turn a working, if crippled, amp into a broken amp.
I guess without knowing the source of the problem its impossible to know if it might cause a cascade failure down the road?