FINALLY something goes my way!

The repair guy in Alamogordo fixed my AV receiver!  He never heard from Onkyo about a replacement board, so he did some digging online and apparently it's a fairly common failure, common enough for their to be repair tutorials.  He dug in with a soldering iron, replaced some caps, and IT LIVES!

$60, plus my original $20 deposit.  Seems fine.  The only glitch putting it back together was one of my speaker wires broke -- at the speaker!  easy enough to fix with a pocket knife.  Plus apparently the digital port is on the amplifier board, not the HDMI board, so if it happens again, I could buy a HDMI switch with an optical out and bypass the HDMI board entirely.