It sounds like the disc sensor cable/connector is broken or the cable is damaged/not fitted correctly. It's the tiny connector with the 2 wires that connect at the edge of the logic board.
The disc sensor will detect the disc and try to suck it in. If this is damaged you would have to force the disc in by hand because the drive can't see the disc. You probably know all this but just in case...
I'm also not sure if the wrong logic board on a drive will accept discs. I remember a post from a BR Drive guru called 'Mark Webber' about this. I would remarry the logic boards and check that. If you can't, i'll swap an old logic board i have over onto my 60gb and see what happens.
Last edited by Castleview; 01-23-2013 at 03:01 PM.