Another photo.. Topside...
The thump is caused be the relay setting immediately.Everything works as it should just that relay clicks immediately and there is a thump in both speakers.
This is not making any since..I have a CA-800 parts unit with and unmolested PS board I think.
Probably needed a volume control to fix another unit.I'd figure you'd fix it up lol!
If you hear and instant click. Its not the relay. Its the control voltage getting there to soon.The slight delay is to allow your regulated power supply to stabilize first.I can't remember for sure now if the old relay clicked immediately, and I tossed it!
Would the relay from my parts unit 620 be the same?
NoHave you checked D709 and 710 out of circuit?
Yes, I researched that because I've had trouble with those in the past.TR709 is a C458LG, correct orientation of replacement?
Zener D706 ok? Would still give an RC time delay
Tested good in circuit I'll pull and test.Zener D706 ok? Would still give an RC time delay
What voltage are you seeing at each end of R721 ?Tested good in circuit I'll pull and test.
Looking at the icon and comparing it to the t existing c458's it may be in incorrectlyTR709 replacement is ecb, check that it matches the icon on the circuit board. Flat face should be facing 2 large caps
EDIT: OK, you've got a different version of the board, also icon may not be correct for that board.