[. . . ] SCSI trouble shooting tip and hints Common SCSI Problems The host adapter isn't recognized on system boot-up. [. . . ] ·Termination power has failed or is incorrect ·Lose cable or cable is too long. ·Cables are too long ·Incorrect, Low or noisy termination ·Bad cables ·Internal SCSI cables are folded creating a resister-capacitor. Helpful Hints 1. The only way to properly troubleshoot a situation is to change one thing at a time to see if that cures the problem. 2. If it does not cure the problem you should reverse the change before make another change. There are many cheap SCSI cables on the market that don't meet SCSI specifications. If so you need to terminate the unused lines or the "high nine". To do this you need a special 68 to 50 pin external SCSI cable with termination built-in for the unused lines. [. . . ] Are you powering on external SCSI devices prior to booting your system? [. . . ]