Sony Receiver str-de805g one channel bad

A friend of mine has this receiver str-de805g. He told me the right channel does not play but when I took a look at it, if you crank the volume, it will begin to play but very distorted. I opened the unit to have a look inside and while a couple transistors looked as though they had gotten quite hot, I couldn't find any real visible evidence of any parts having burned up such as a blown electrolytic.

Does anyone know of anything specific I should take a look at or do the symptoms sound familiar?

Thanks
 
I've done a little more inspection and it seems that the distortion is present in the headphones also when speakers are switched off. The volume control actually doesn't seem to change anything as far as the distortion goes and it is the same on every input.

I suppose all I've really determined is that the problem is not the volume pot, the power supply, or the power amplifier. It doesn't seem to be any individual input so it seems to me there are only really 2 boards that could contain the faulty pieces. The front board which is basically the signal processing; surround, environmental and the like, or the last board between the inputs and the power amp section.

Let me know if there is any help to be had here. Thanks.