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Question for technicians

Recently I noticed my system was sounding dull and flat. Then I discovered there was little to no sound out of the right speaker, just an intermittent weak signal accompanied by static. Later, I noticed that I could make the signal come and go by merely touching the preamp's input selector switch, or applying a slight push-or-pull pressure to the control knob. I don't have any audio shops around here that I trust and I can do simple things like solder touch-up, continuity checks with a vom etc... Any ideas of how to go about checking this out? (greatly appreciate any and all advice)
rawinsonde
rawinsonde OP
47 posts
 
Thanks, folks... I was thinking about touching up the solder points but the contact cleaner idea makes more sense to try at first. With me not being skilled at solder, I guess I could actually create additional trouble. I'll see if I can find some of that Caig ProGold
atmasphere's avatar
atmasphere
12,098 posts
 
Use the Radio Shack contact cleaner first! The ProGold can cause trouble in some circuits (I've seen it contaminate circuit boards to the extent that they had to be pressure washed to remove the ProGold)!! IMO/IME the Radio Shack contact cleaner is the only thing you want to use as it is safe with just about any circuitry, especially if vacuum tubes are involved.
csontos
1,311 posts
 
Ralph, what is your opinion on Deoxit? There are no Radio Shack stores in Canada.
atmasphere's avatar
atmasphere
12,098 posts
 
*Sparing* use of Deoxit (DN5) will work fine. Keep it away from circuit boards if you can. Its more powerful than the Radio Shack cleaner and tends to have more capacitive effects (although slight) from what I can tell.
rawinsonde OP
47 posts
 
I bought a can of CRC (QD) Electronic Cleaner. I did this before seeing the last 3 posts as I figured this stuff was all basically the same thing.

After removing the knob with a small allen the shaft seemed to have no wiggle room going into the faceplate... extremely tight clearance. I sprayed liberally around the "opening" and worked the control back and forth hoping the cleaner would penetrate. On the other side of the faceplate (inside the chassis) the switch shaft goes into a housing of some sort where I can't get at it there.

When I hooked the preamp back up and tested it worked fine for a couple of days but now it is occasionaly failing again. Each time it fails I simple jiggle the selector to balance the sound again. But it only stays good for a while.

Since the cleaner did seem to have an effect, I guess I will repeat the same action with the cleaner, only work it more and for a longer time.

Any further ideas or suggestions? (thanks)
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