problem with Marantz amp PM-80SE

I am trying to repair a Marantz PM-80SE no output.
Does anyone have a service manual of this amplifier?
I already did some measurements open and check transistors
Caps resistors voltages supply rails. Seem look okay. But no quiscent current bias not working output device doesn’t warm-up
Replaced STK 3102 IV by an STK 3102 III but no change. IV III stands for what? Are these upgrade versions, datasheet pin out are same. Any help is greatly appreciated.