Since I posted my original question about the failure of my JVC hall synthesizer...
Several years ago, when I turned it on after a long period of disuse, the VF display was scrambled and the unit didn't work. I let it "cook" for a day, and the (apparently) malformed cap that was causing the problem decided to behave itself.
Several weeks ago, I finally got my rear amplifiers, so the JVC was restored to full-time service, and was working magnificently, until... You guessed it.
About a half-hour ago, the display went dead and the outputs turned into a not-too-loud digital "buzz". The input is locked at "digital". (The default is analog, and you have to manually switch.)
My guess -- and this is only a guess -- is that this a power supply problem. (The fact that all the channels went out does not automatically eliminate any of the LSIs, unfortunately.) I have the service manual, but before I start ordering mass quantities of electronics (or even start checking voltages), I'd like to know if anyone has any views.
Please note that I don't expect anyone to diagnose what might be a messy problem from a distance. (I'll call JVC tomorrow, anyway.) I just wanted opinions.
...I've done some more checking. I found that if I let the unit sit overnight, it comes on again -- then fails after a few minutes. I've been able to repeat this.
This suggests some component is failing then reviving. (Duh...) As the symptoms -- dead display, input locked to digital source, low-level buzz at all outputs -- are not likely to be caused by the failure of a single chip, the likelihood of something in the power supply -- in this case a bad cap that "comes and goes" -- seems likely.
Any thoughts?
Thank you.