Have you checked that the drive is terminated properly, and that if you have parity selected in the BIOS to make sure that it is setup on the CDR.
Another thing to do is to check to see if it has enabled DMA access to the drive.
OR
You can make a boot disk and launch into DOS and see if your drive works there if it does then its a driver issue and see the above point if it does not work then it could be the drive is either damaged or that the SCSI card and CDR are not comunicating due to:-
* Not terminated properly
* Both not set to Parity only
one or the other
* IRQ conflict
* DMA turned on for CDR
* OR just coincidence CDR is broken
