AT&T MERLIN LEGEND Installation & Maintenance Manual page 507

Maintenance and Troubleshooting
Follow these steps to check carrier problems:
1. Visually inspect the pins on the carrier. (Bent or broken pins
often cause carrier problems.) To do this, you may have to
remove one or more line/trunk and station modules by using
Busy-Out, Reset, and Restore.
2. If you find a problem with the carrier, you must replace it (but
not the line/trunk and station modules). Carriers cannot be
repaired in the field.
Attach a tag that describes the problem to the faulty carrier.
3.
Replacing the Power Supply Module
Failure of the power supply shuts down everything connected to
the carrier.
If the power supply fails, check that the interlocking post in the
power supply slot of the carrier has not broken off. Without this
post, the power supply will not operate and the carrier must be
replaced.
Follow these steps to replace the power supply module:
If possible, save the translations on a floppy disk by using the
1.
backup function.
Note: If the power supply module on the basic carrier has
failed, the system cannot save the translations to a disk.
2. Power down the system by turning off
a. the power supply module on the basic carrier
b. the power supply module(s) on the expansion carrier(s)
c. any auxiliary power unit (if present)
3. Unplug the system from the AC outlet.
4. Remove the power supply module and insert a new one.
Maintenance 5-29