Finished restoring a real nice non working 980, recapped all boards, replaced transistors throughout, also replaced diodes..all according to previous parts lists. Now the problem, the unit will not come out of protection, the right amp will not adjust to 0.00VDC offset. The left channel is fine, the right channel fluctuates between 2.0VDC and 6.5VDC. Checked and rechecked all caps and transistor placements all looks good. This is all on 100 watt DBT, I haven't juiced it up full house power yet. Here are some readings from PS and Amp card:
Power Supply: AWR-156 spec in brackets
pin 20: +36.0 (33v)
pin 22: +51.50 (50v)
pin 23: +24.50 (23v)
pin 25: -24.85 (23v)
pin 27: -51.85 (50v)
pin 28: -13.25 (13v)
pin 16: +13.25 (13v)
pin 18: +12.85 (7.v)
Right Amp Card AWH-073
1. -51.85
2. +16.75
4. +24.50
8. +54.75
12. +43.65
22. -43.65
Right and left amp cards are measuring the same except pin 10 which is the DC offset measurement. Idle current is easily dialed in to spec also.
Power Supply: AWR-156 spec in brackets
pin 20: +36.0 (33v)
pin 22: +51.50 (50v)
pin 23: +24.50 (23v)
pin 25: -24.85 (23v)
pin 27: -51.85 (50v)
pin 28: -13.25 (13v)
pin 16: +13.25 (13v)
pin 18: +12.85 (7.v)
Right Amp Card AWH-073
1. -51.85
2. +16.75
4. +24.50
8. +54.75
12. +43.65
22. -43.65
Right and left amp cards are measuring the same except pin 10 which is the DC offset measurement. Idle current is easily dialed in to spec also.