Digital Equipment RW504-ZA, Service Manual

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Table 4–1 (Cont.) Operation/Installation Troubleshooting
Task Problem/Symptom What to do
The unit’s power failed
while a disk was in the
drive. Try powering on the unit. If successful, use
the file system check command.
If power-on is unsuccessful, power the unit
off. Do not move the unit. Moving the unit
with a disk in the drive risks damaging
the magneto-optical mechanism in the MO
drive. Refer to the ‘‘Powering On’’ and
‘‘Power Fail’’ sections earlier in this table.
If it is critical that the disk be removed
from the drive before power can be restored
to the drive, see Section 4.4.
4.2 Power-on Self-tests
CAUTION
When the optical disk library is powered on and the self-test is run,
the SCSI interface and the terminator must both be either connected or
disconnected.
If the controller senses that the optical drive is not connected to a host
system via the SCSI interface, additional self-tests are run on the SCSI
circuitry. If these tests run while a terminator is attached, voltage levels
at the SCSI bus connector are different than expected and a self-test
failure results.
CAUTION
Do not switch off any peripheral on the SCSI bus without first checking
that the bus is not active.
Switching off can cause data loss and/or indeterminate bus states.
To run the power-on self-test, do the following steps:
1. Insert a formatted disk into the drive either from a storage slot location or
through the mailslot/control panel.
2. Remove power from the optical disk library. Press both the power switch on
the back panel and the operation switch on the front panel.
4–6 Troubleshooting and Diagnostics