I'm troubleshooting a big buck hunter where the Bird and Ram opto switches are stuck closed in test.

I have replaced the optos.
I have replaced the opto amplifier board.
All of the other switches in that row work fine.
I have not tested the other switches in the Ram or Bird opto column.
As soon as I plug in the 5 pin connector on the opto amplifier board, the switches are stuck closed in test.
As soon as I plug in the switch drive connector at J1 in the backbox, the switches are stuck closed in test.
The opto switches are not glowing red at any point.

Is it likely a transistor for those switches? Anyone know which transistor it is? The BBH manual is not the best.

Any help would be appreciated!

Thanks for the reply. The lights on the opto amplifier board flash and go dead as soon as I plug the 5 pin wiring harness in. This happens with and without the optos plugged into the board.

I reseated all of the wires in that 5 pin connector.

This opto amplifier board came from a known working game.

Yes.