Try connecting a different disk drive to the system. If the system sees the other drive, then the problem is in the disk drive and not in the computer.
If the problem is found to be in the disk drive, check the drive select jumpers on the drive. The drive should be set to "cable select" and attached to the last ("master") connector on the cable. I have,however, seen a few older Maxtor drives that fail to respond when set to "cable select," but run successfully when set to "master."
