Is it worth fixing to sell Parasound P DD 1500 Digital Surround Decoder

I have a vintage Parasound P DD 1500 Digital Surround Decoder which powers on but does not switch to 2 channel or Pro Logic out of Dolby Digital. I assume all the other functions work but my question is does this have any value to fix and try to sell? I appreciate any help.

I think it would probably cost more to try to fix this as it sounds like a digital circuit problem.  It looks like recent sales were $77, $99, and $185, so I would say it's not worth trying to fix.