Owner has seen this thread
Easy to blame PbF as printed all over as such. Problem is different to that above thread. For ages now the R ch has failed occassionally at switch on. Switch off and most of the time it comes up. Very rarely that ch dies in use, Then last week both ch failed at sw on , so he decided something needed doing
Anyone know how to find mechanical data on 16 amp output relays Make Finder 40.615 , clear cased so can see the contact gaps About .75mm for the R one and .5mm or so for the L. Thinking fine contact contamination and not enough mechanical punch-through. Both relays in series from one supply and TA3717 ptotector IC Or any other ideas other than checking phones socket, if wired in to affect output somehow, PbF solder looks fine. Wanging with engraver and nylon bolt has only highlighted a microphonic capacitor.
Looks like another amp where I'll make an LED mod that the owner can view through the phones socket. Bring out pcb mounted, relays-on LED ,and add a different colour one for the main rails supplies on, both viewable through the phones socket transparent plastic panel at its rear