I just resurrected a YLOD 60GB PS3, I suspect that its only issue was that every void inside it was full of dust. As this was the first PS3 I'd had apart, I didn't realise that fixing the YLOD would probably allow me to eject the game stuck in the Blu-Ray, so when I removed the drive during the teardown I opened it and manually removed the disc. Now when I try to insert a disc the two little plastic tabs at the front don't drop out of the way, preventing the disc from entering the drive. If I hit eject there is some clicking from the drive, though it doesn't sound right - any hints? I'm guessing I'm going to have to yank the drive again...
The drive mechanism will need to be reset. You'll need to remove the loading mechanism motor (in this photo, it's labelled "Lademotor" (I'm thinking it's german). The two sliders on either side of the laser deck will need to be reset (left slider goes all the way towards the back, and right one all the way towards the front). Then put the motor back in place and when attaching the upper cover assembly, make sure it all feels like it's going together naturally (you shouldn't have to force it).