Memphis mojo 4kw

[Triviumfan4]

Can anyone give me an idea how the output drive works and what parts are involved with it on the main board.
The amp powers and relay engages.All power supply/regulators seem to be working.
Outputs are installed but no oscillation.It did have some shorter outputs.
I'm not exactly sure if there are driver transistors on the main board.Its a little tricky to trace because it's multilayered.
Also the rectifiers marked 30EPF06.Whats there purpose in the circuit?

 

[Perry Babin]

QA1, 2, 3 and 4 are the driver transistors for the output stage. All of the drive is produced on the driver board, passes through those 4 driver transistors and then to the output transistors.

Those diodes are likely used to route any voltage/energy generated by the output circuit (the voltage that causes 'bus pumping') around the output transistors. Someone should correct me if that's not correct.