QSC PLX3602 Amp power cycling

[AV-BenchTech]

Anyone had their Amp fail and do this and fixed it? I found Q79 in the output stage driver circuit dead shorted. But that alone didn't fix it. Protection circuit still shutting it down.

 

[americanaudiophile]

Bad bias resistors? Check the caps too.

 

[AV-BenchTech]

Had checked pretty much already checked most of the diodes and transistors at that point, and most of the critical caps also before I found Q79 shorted. Turns out Q79 was the only fault, I just never plugged the fan in when testing the repair. Once I put the unit back together to ship it out to factory it was working fine! Thnx