I went sniffing around for prices on used units and found this:
| ~$350 - $450 | Units listed for parts or not working, often with known defects like a broken amplifier board. |
I guess it happens often enough. I can just see Mark waving that shillelagh screaming, "What have I been telling you, you
fools! Now go clean your ears!"

I would f^%&ing cry if my amp board fried.
I still haven't hear the OP say he went into the manual set up and made sure he hadn't turned his amps off or listed the speakers as 'None" in the Speaker Configuration part. I almost feel like PENG could wave a magic wand from Canada and just fix it if he was so inclined.
OP, I'm pullin' for ya! I'd love to hear that you got it to work somehow.