Yes, I know it's very old thread and Yes - I am grave digging.
Yes,
@TLS Guy - It is junk electronics

but mine was built in japan, not that it helped it.
I can't quite believe that, but my 805 is now developed same issue. Factory reset already tried and didn't help. Besides lacking LED display - all other functions seem to work just fine, but I feel it's definitely one step closer the electronics heaven... (or hell in case of Onkyo)
Well, it lasted me 10 years - and I think it's sort of the record for 805 series...
I'll try this fix as I'm pretty comfortable with solder and warranty is long gone anyhow
http://www.avsforum.com/forum/90-receivers-amps-processors/857502-onkyo-tx-sr805-thread-434.html#post15249416