IBM 704 - Manual (Page 261)

SCSI Messages
SCSI Messages
If your server has at least one hard disk drive, review the following
information before having the system serviced.
Note: If your server has a CD-ROM drive but does not have a hard
disk drive, ignore any message that indicates that the BIOS is
not installed.
SCSI Messages Description
All One or more of the following might be causing the problem.
A failing SCSI device (adapter, drive, controller)
An improper SCSI configuration
Duplicate SCSI IDs in the same SCSI chain
An improperly installed SCSI terminator
A defective SCSI terminator
An improperly installed cable
A defective cable
Action: Verify that:
The external SCSI devices are turned on. External
SCSI devices must be turned on before the system.
The cables for all external SCSI devices are
connected correctly.
The last device in each SCSI chain is terminated
correctly. (See “SCSI Drives” on page 159 for more
SCSI chain information.)
The SCSI devices are configured correctly.
If the above are correct, run the diagnostics for additional
information about the failing device. If the error recurs, have
the system serviced.
Chapter 5. Solving Problems 243