What to do with a dead receiver?

[Nailhead]

I have a dead receiver that has been collecting dust for some time now. I bought it about 3 years back. It is an Onkyo HT-R520 that was part of a HTIB system for $400, still have the speakers, just need a working receiver.

I don't know what is wrong with it, it turns on, but just no sound and acts as if nothing is even plugged into it. I have done a good bit of research on the net to find other people with similar problems, but nobody seems to have the same problems I have, so my only option is to trash it, or take it to a shop where they will probably want me to pay them more than the thing is worth.

What do you think I should do?