Circuit !!! Failing that, measure the output offset voltage on each channel before the relay. If it's OK, it's possibly a problem with the protection circuit itself.
Also check for dry joints throughout but particularly ANY power transistor anywhere in the amp & PSU etc, older Jap stuff is terrible for this problem, and when you try and resolder you find the solder "won't take".
Remember the relay is either "telling" you there is a problem with offset voltage or the protection circuit itself is misbehaving. Checking the offset voltage will confirm which it is.
My moneys on a DJ or very unlikely, a transistor that is intermittant open circuit, which is another weird affliction of Jap transistors.
Good luck
Also check for dry joints throughout but particularly ANY power transistor anywhere in the amp & PSU etc, older Jap stuff is terrible for this problem, and when you try and resolder you find the solder "won't take".
Remember the relay is either "telling" you there is a problem with offset voltage or the protection circuit itself is misbehaving. Checking the offset voltage will confirm which it is.
My moneys on a DJ or very unlikely, a transistor that is intermittant open circuit, which is another weird affliction of Jap transistors.
Good luck
Hi,
Impossible to say. You have to take measurements to at least isolate which area the fault is in, even if you don't know how to fix it. A dry or intermittant transistor would certainly behave as you describe.
Do you know what we mean by "offset voltage" as that's the first thing to check when any protection circuit keeps the speakers disconnected.
Impossible to say. You have to take measurements to at least isolate which area the fault is in, even if you don't know how to fix it. A dry or intermittant transistor would certainly behave as you describe.
Do you know what we mean by "offset voltage" as that's the first thing to check when any protection circuit keeps the speakers disconnected.
http://www2.yamaha.co.jp/manual/pdf/av/english/IntA/CA-610.pdf
Start with replacing the timing cap for the relay, C461.
Start with replacing the timing cap for the relay, C461.
I checked DC Offset at speakers and I get 5.1mv and 3.3mv. I am reluctant probing on the board with unit "powered ON". Is there any other test I can perform or should I just buy new capacitors and replace and hope? According to the shematic, there is about 33 electrolytic caps. Do I need to replace ALL of them? Maybe I have a bad transistor too?
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