when it's not the output stage that fails on the denons, it's some power supply that is not in the tolerance.
check every power supply output, one must be missing or out of specs.
the schematic of the amplifier is mandatory to fix them.
Can't test voltages on something that doesn't turn on

I found the issue though.
The 78/7915 regulators that are known to fail, had been replaced before.
However, the rectifier and current limiting resistors that feed the regulators had failed.
Two diodes were short circuit, and half the resistors had gone open circuit.
I had tested the regulators themselves out of circuit.
I've replaced them again now anyway
