It could be a number of things. You really need to give us an idea of the hardware in the machine Hard Disk card type etc 2091?. Apart from that it might be an idea to get a good set of 1.3 workbench disks, format the hard disk and reinstall. If there is any data you want to keep you will need another disk drive to backup to. Finding another working 50pin SCSI drive could be a problem depending on where you are.
