Help! Adcom GFA 585 DC High offset problem

[birdyman]

I followed Adcom experts recommendation on restoration of Adcom GFA 585. I washed input board 2x with Simple Green cleaner and brush. Then I replaced all electrolytic caps with Nichicon Muse or gold caps. DC offset without speaker connection was 900mv left side and -9v right side. This was same reading after first wash. So apprently, second wash ( which I soaked boards in simple green for over night before using toothbrush to scrub both boards. I just received OP97 from Digikey, I replaced the right side opamp (-9v offset side). OP97 did not do any improvement. Dc offset is initially -9v as I turn on the amp and it drops to -2v over 5 min or so. Strangely, if I turn amp on offset is -9v but as I switch off Dc offset drops immediatly to 0.9v. I have not replaced zener diods yet. What can be possible cause for this?

[birdyman]

Last night, I went through and I found reversed cap (stupid of me) on the channel with -9v offset. I corrected cap polarity and replace opamps to OP97 on both channel. DC offset is better but it still is about 2 volt with or without speakers connnected on both channel. But it still drops to less than 1v immediately when power switch is off.

[birdyman]

I found that DC offset become less when I lift a leg of registor that connects output of opamp to long tail pair(input stage transistors). I replaced opamp which did not result in resolution. I found 10 ohm resistors on both board on feedback circuit was open. Now my amp is fixed with less than 50mv DC offset. It is great sounding amp indeed.
Here are steps I took to fix
1)Removed all electrolytics caps and bias pots and heat sinks from input boards
2) washed input boards 2x with Simple Green sprey and tooth brush( got it from Lowes)
3) Replaced DC servo Opamps with OP97(got from Digikey), replaced ALL electrolytics with Nichicon Muse caps and soldered bias pots back.
4)Replaced open 10 ohm flame resistant resistors( these are the diffrent color resistors on input boards) on feedback/dc servo input stage.