9090 no bias current one channel

[tutor_turtle]

I fixed the bias issue (2sc984 bias control x-stor was bad)
I have a 9090 (not db) that came in for shorted outputs (in protection).
Rebuilt the driver board, replaced the outputs.
Comes out of protection, bias and offset are good, but I don't get a green light.
Sound quality is good.
Pulled the driver board, red light flashes for a second, comes out of protection, no green light.
On the F2547 Protection board, contacts numbered 15, 16, 17 go to the protection LED. (F-2548)
Which connection is for Green? 15 or 16?

 

[Hyperion]

On the F2547 Protection board, contacts numbered 15, 16, 17 go to the protection LED. (F-2548)
Which connection is for Green? 15 or 16?

As I understand it, 16 & 17 are green. There is a contact on the relay RL01 which routes power either to the multivibrator (for flashing red = Protection mode), or disconnecting the multivibrator and connecting the green LED (for solid green = Out of protection mode).

Note R12, 1.5KΩ resistor in series with pin 17 is notorious for burning and going 'high resistance' or 'open circuit' due to years of running the green LED.

Regarding No Bias on one channel (after OP transistors blown up and replaced), check the 4.7Ω base resistors for the OP transistors.

 

[tutor_turtle]

As I understand it, 16 & 17 are green. There is a contact on the relay RL01 which routes power either to the multivibrator (for flashing red = Protection mode), or disconnecting the multivibrator and connecting the green LED (for solid green = Out of protection mode).

Note R12, 1.5KΩ resistor in series with pin 17 is notorious for burning and going 'high resistance' or 'open circuit' due to years of running the green LED.

Regarding No Bias on one channel (after OP transistors blown up and replaced), check the 4.7Ω base resistors for the OP transistors.

Thanks R&C.

The green lamp was working until I made the rookie mistake of failing to account for the change in pin orientation of TR09 (KSC3503) on the driver board, which took out two +/- 64v 10A fuses, D06 varistor, bias control transistor and two outputs all on the right channel. That was an expensive and time consuming mistake.
I will check R12, but I'm wondering of I could have also taken out diode D03 (F-2547) on the OP board?

Best regards, Steven

As I understand it, 16 & 17 are green. There is a contact on the relay RL01 which routes power either to the multivibrator (for flashing red = Protection mode), or disconnecting the multivibrator and connecting the green LED (for solid green = Out of protection mode).

Note R12, 1.5KΩ resistor in series with pin 17 is notorious for burning and going 'high resistance' or 'open circuit' due to years of running the green LED.

Regarding No Bias on one channel (after OP transistors blown up and replaced), check the 4.7Ω base resistors for the OP transistors.

R12 open.
Mocho Thanks Hyperion.