Marantz PM-17 repair

[hirafu_boarder]

I have been asked by my friend to take a look at his Marantz PM-17. He says he was using it as a power amp (via the Main In) connected to a DAC with volume control which got fried and subsequently damaged the amp.

Doing some simple tests, I can see that the left channel still seems to be fully functional. But the right channel speaker output is completely silent.

The pre-amp section (input selection and volume control, and pre-out) all seem to work fine for both channels.
The headphone output is also good in both channels.

So the damage seems to be limited to the right speaker output.
I can detect a faint odour of fried electronics, but haven't yet removed the boards so cannot visually identify the deceased.

Could somebody offer some advice to diagnose the parts to replace?
A search indicates that the PM-66 model is pretty popular for mods, so perhaps someone could offer general Marantz advice. rowemeister??

Here are the schematics (partial service manual).

http://www.audio-circuit.dk/Schemati..._amplifier.pdf
(warning large file)

Many thanks,
Jeff