I am measuring a short between 4 and 2. So out comes the modulator pcb again... and find out why.
More of that damn SMD glue. that little red glue is starting to become conductive. couple of caps and resistors near U10 once heated and moved around, the short went away.
I've never seen the red epoxy used to hold SMD parts in place before soldering but there is a beige fixative that turns dark and can turn to a reddish color that does become both corrosive and conductive. If that's what you have, you need to remove all of it from the amp.
I dont know exactly. I do know it has something to do with the glue or whatever, because these random shorts preventing the amplifier from working, clear up when resoldering components. My guess is the glue.
If you are still looking for some help I have access to schematics and have worked on this board a number of times. Pins 9 and 11 are the outputs of the LM361, but only Pin 11 is being used. Pin 3 is the audio input and should be low,I suspect the feedback loop is interrupted.This could be a problem on the sub 2 board(I think)-drive for the output mosfets or the output coil may have a broken lead or cold solder joint(If its a broken lead the coil may need to be replaced,cold solder is easily remedied).I will check my schematics on Monday when I return to work.
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