I've just tried it with a dreamcast GD and a music CD. The disc spins but doesn't seem to be recognised. Any Help?
To start, I'd get a cotton swab on a stick (namebrand: q-tip) and put some rubbing alcohol or glass cleaner on it and gently clean the laser lense. This fixed one of my retail units that I thought couldn't read discs anymore. If that fails, have you tried reflashing the firmware?
If it wasn't his on eBay a few weeks back, then I think he was just posting to see if it was a fixable repair before bidding on it.