I would try disassembling it and removing that optical drive. An optical drive with a stuck disc (esp. after a crash) can produce very ugly symptoms. I've seen a couple of Powerbook and iBook G4s that seemed dead until I took them apart, disassembled the optical drive, and removed a stuck disc.

Happily, not only did they work when everything was put together, but the optical drive's mechanism reset itself too, making the drive usable again.

But even if this doesn't work, and even if your mini is dead, I agree with you - it's a great conquest and you can make your investment back on parts (some dude who wants to put a nano-ITX board in there would probably we willing to pay at least $50US for just the case).

M