seacue,
CD-ROM Drives are very cheap. With CD-ROMs running under $15.00 and CD-RWs running about $32.00, DVD/CD-RW Combo Drives running about $47.00, and DVD+/-RWs running about $92.00 it is not worth trying to repair them.
The tray mechanism is the weakest part of the optical drives and just a sideways jolt while open can damage them. This has been a problem with these types of drives since they first hit the market. With the prices on the drives continuously dropping, I do not expect it to change in the near future either.
Take Care,
Richard