Reference my post #3,689 ......
I've been looking at
@voxxonline's 'problem' with his Wolverine - reference his posts just before mine. He sent his amp to me to fault-find and in case this may assist anyone else on the forum this is what I've been able to conclude:
He felt that 'something happened' as he was connecting his speaker wires, because inadvertently the amp was still turned on at the time. Only one channel was believed to be affected. He was aware that the speaker binding posts were not good and needed to be replaced, and this indeed was the source of the problem I believe - any very slight movement caused the posts to short out onto the chassis rear plate.
Symptoms:
I used a 'bulb lamp tester' and, when power switched on the lamp was brightly lit and 'pulsing' rapidly. Immediately switched power off and measured the boards - one channel direct short between speaker + to both V+ and V-, other channel looked OK.
Resolution:
Process of elimination, found output transistors Q110 and Q113 both short circuit, remaining transistors suspect. As a precaution, all output transistors replaced with new. Switched on again to test, and 'pulsing' still evident. Further process of elimination revealed Q104 (VBE) also 'blown'. Replaced Q104 with new - all now working as expected.
Testing/setup:
Ran through the set up from scratch for both channels (5v, bias, DC offset) - all good. Played some music to test and all now seems to be fine!
Conclusion:
Suspect speaker binding post(s) shorted to chassis, which caused surge/spike and blowing of output and VBE transistors.
All's well that ends well.
Moral of this story - make sure your amp's turned off before playing around with wiring and connections!!
