Mark D. Zacharias said:
The ground screws were a problem years ago - now if it's a similar
problem, it would more likely relate to a soldered ground connection
associated with the rear panel. I agree the OP may have introduced a
failure, though. Close inspection of his work is indicated, and the usual
DC voltage checks to narrow down the protection problem. May very well
wind up being over the OP's head to fix this one.
Mark Z.
Hi Mark
Well, I have sent the schematics directly to him as he requested, so it's in
his hands now. I've heard nothing back so far ... I still fool myself on
various amps with grounding issues - and how many years have I been at it ??
Just yesterday, I did a Pioneer amp that was intermittent as hell. To get at
the board bottom involved taking it right out, and also removing the rear
panel to get enough clearance to hinge it up. It was littered in obvious dry
joints ( it looked like he dreaded lead-free solder ), so I reworked them
all, and confidently stuck the board back in, screwed it back down, and put
a couple of screws into the back panel just to hold it in place. I switched
on, and it all worked ok - until I moved it on the bench that is ... It
promptly cut out into protect. Several minutes of cursing later, I realised
that a couple of the RCA jack assemblies had metal fingers up the fronts of
them. Once the screws had been put in these to bond them firmly back to the
rear panel, all was well, so this is something that the OP should definitely
check, as you say.
Arfa