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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
elizabeth
6,726 posts
 
Take the top off and inspect the selector switch. A wire may have come loose.
Agree a spray contact cleaner can do good too.

If the switch is free standing it is an easy to replace part. If it is attached to the cucuit board directly, that is harder to do.. as you need the exact replacement to fit it.
bombaywalla's avatar
bombaywalla
1,957 posts
 
I agree with both Ozzy & Elizabeth - get hold of Caig ProGold contact cleaner OR anything similar from your local Radio Shack (if they still sell this stuff anymore?) & spray onto the contact of the inp selector & turn that selector switch back-forth thru all its options again & again to work that contact cleaner in. If there is any oxidation it should resolve that issue.

Elizabeth also has a good suggestion - check the soldered connections to this switch. you might have a weak solder point. this can be easily fixed by reflowing the solder.
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
7,068 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
1,275 posts
 
Ralph, what is your opinion on Deoxit? There are no Radio Shack stores in Canada.
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