On Friday, June 22, 2018 at 4:35:46 PM UTC-4, wrote:
This is my own receiver. Last year it started taking longer and longer for the protection relay to activate and turn on the speakers I finally took it out of service. I recall that it had no other problems that were evident. I had posted this problem at that time and I think that it was Chuck up in Canada who nailed it immediately. He recommended changing C6 on the protection board and .that resolved the protect relay problem. Now however there is another problem that I never had before. Most of the dial lights including the signal meter light are out and that meter also seems to be inoperative as well. I never had any trouble with any lighting or the signal meter on this receiver. This is a big quadrophonic receiver. The switching is done through the main selector switch and it's a nightmare to get to. A real rats nest. Does anyone who has worked on these recall any common problems with lighting on one of these? I suspect a ground problem because so many of these lamps are in parallel but it's so crowded in that area you can't see anything. I Really appreciate any help. Lenny

Hey guys I really need some more help with this one. It's on the bench and even though I'm working on it my wife is flipping out over the entertainment center all torn apart in the living room. But that's a woman for you, can't appreciate the beauty of a repaired 1974 receiver...

Anyway in looking at the schematic I can see that there is a 6 volt winding referenced to ground. The blue 6 volt transformer wire goes through a 5 amp fuse the output of which directly feeds AC to a bunch of lamps in parallel. The output of the fuse also feeds a rectifier and filter which then feeds DC to some other lamps through some other switches. I just can't make any sense out of it.

For one thing although I can see a multi pole switch feeding individual lamps and I'm assuming they are indicators I can't tell for sure which lamps are for which function, (panel lights or indicators) and so I'm not certain where to jump because I can't tell which lamps would need to powered by AC or DC. Most of the ones that seem to be indicators such as phono, tape, etc.. seem to light now and it would be nice to retain that after jumping out whatever I need to to restore the other lights.

Another weird thing which is also troubling is that every once in awhile the signal meter seems to illuminate although it doesn't seem like it's fully bright and there is never any signal level response on it. I never had trouble with that either. Can one of you guys please help me with determining where to "jump" the switch and get all the lamps working? Then I'll have to figure out this signal meter problem. Thanks, Lenny