Looking at the schematic it looks like the balanced amps are there as well and maybe this is due to those unbalanced adapters that short the negative active pin to ground. The level of incompetence is clearly displayed in this unit- lose screws, wrong screws, meters with wrong lamps and it goes on. It even had a tachometer on it that was not even from this model.
I have been changing out the 220uFd and 100uFd Marcon caps as I have found some shorted in other decks already. I don't think they age well.