MOSFET Amplifier cleaning

indianjjy · Joined: Apr 02, 2008 Posts: 6 Location: fort worth,Texas

To all, I just bought a well abused guitar amp,70's solid state but it is a MOSFET style. Is there any special instructions on cleaning this curcuit board ? It is very dusty and dirty,pots are very scratchy, but it does perform well. As info it is a RANDALL RG90A commander 2. Any help on this matter is greatly appreciated. Everyone on here has helped me alot. I must have lost alittle too much grey matter in the 60's. Thanx Razz

Werebo · Posted: Sat Apr 26, 2008 5:48 pm Post subject:

For the circuitry, a stiffish brush and a can of compressed air should clean most of that dust out. I seem to remember that MOSFET transistors were particularly susceptible to static electric zapping them, so take care when handling the component side of the circuitry. It might be one of the few instances where I'd recommend wearing an 'Earth/Grounding strap' round you wrist.

Unfortunately, there isn't a great deal that can be done for scratchy pots, apart from replacing them. For a short-term cure, a quick squit of 'WD40' works wonders for getting rid of scratchiness, but it doesn't last long.

If you have a component store nearby (or can order them online), they're not too difficult to replace, just make a quick diagram of which wire to what terminal. The hardest part of the job will likely be actually getting them off the mounting panel Wink.

Some amps were a joy to work inside, everything was easily accessible, others were pigs, seeming to need every last nut & bolt removing to do anything.

I'm not familiar with 'Randall' amps, but from your description and the fact it's working good, it'll be worth spending the few $$$'s in getting it up to scratch.