I've got an old Roland silver Cube amp. It's worked great for years, but now the volume drops precipitously at random moments shortly after it's turned on. After it's warmed up for 20 minutes or so, the volume drops cease. What could be causing this?
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1first random thought is a cold solder joint problem, but you say it worked fine for a long time, so second random thought is thermal stress-induced solder joint problem. Not an answer because I wouldn't know how to properly diagnose it.– YorikMay 11, 2022 at 21:03
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5If you want it to work again, take it to a tech. If you want people on the internet to make guesses with way too little information, ask here.– Todd WilcoxMay 11, 2022 at 21:38
2 Answers
This kind of problem usually requires a repairman to open up the amp on the bench and start tapping parts to see what causes the amp to malfunction. If tapping parts gets us nowhere, then we start start measuring voltages and reading schematics to locate areas in the circuit that don't match voltages listed on schematics. needless to say, the amp must be malfunctioning when this step is being performed. Other items to check are defective solder joints, dirty or corroded connectors, problematic guitar cables, or even problems with the instrument. Be prepared to have everything tested.
As a electronic engineer who makes pedals/amps as hobby, I would say that mostly will be happening by aged solders and connections, or anything leading for a inconsistent polarization of the transistors. Probably, anyone with some electronic technical knowledge could help you remaking some soldering or replacing some transistors