Customer amp came in not working. With the bottom plate removed, I found part of the PS FETs shorted plus 1/2 of the output shorted.
The parts replaced in the PS; bank of FETs, (2) gate resistors and the gate drive IC. Parts replaced in the output, HS/LS half bank, (2) 15v zener diodes, (1) gate resistor, and the PWM generation IC.
With the parts replaced, the amp built rail voltage and PWM on the LS. Amp also passed signal testing.