Scsi Bus Troubleshooting (All Models) - Digital Equipment VAXstation 3100 Maintenance Manual

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Troubleshooting 37
Table 2-9 Model 40 SCSI Bus Address ID Assignments
Dence
Addrel!ls ID
SCSI-A Bus
RZ23 disk drive (system disk)
3
Internal TZ30 tape drive
s
Reserved for expansion 1
SCSl·B Bus
RRD40 compact disc drive (internal or external) 4
RZ23 disk drive
3
RZ23 disk drive (additional drive on SCSI-B bus) 2
RZ55 disk drive expansion box
1
RZ55 disk drive expansion box (second box)
0
SCSI bus controller 6
TKSOZ expansion box
5
Reserved for expansion 1
The procedures for troubleshooting devices on any SCSI bus nre similar. You
must remember what devices nre on the bus and know the different codes for
these devices so you can identify a faulty device just by looking at its code.
Three items to remember when troubleshooting the SCS1-B bus are that the
tape device at SCSI address ID 5 is external, the two disks at SCSI address
ID 3 and 2 are user disks, and the RRD40 compact disc drive at SCSI address
ID 4 can be either internal or external. Refer to Section 2.15 to troubleshoot
either the SCSI-A bus or the SCSI-B bus.
2.15 SCSI Bus Troubleshooting (All Models)
To troubleshoot a SCSI bus and its controller (SCSI-A or SCSI-B), run self-test
or the system exerciser.