AT&T MERLIN LEGEND Communications System Release 2.0 Maintenance And Troubleshooting Manual page 99

Control Unit Problems
Checking the Auxiliary Power Unit(s)
Symptom
The LEDs on the multiline sets that are connected to the last two
modules in the carrier do not light up.
The last two slots in the carrier do not have power.
The power supply LED is off.
If these symptoms occur, replace the auxiliary power unit as described below.
Replacing Auxiliary Power Units
See Figure 4-3 throughout this procedure.
1. Make sure that the switch on the power supply is turned off.
2. Unplug both the power supply and the auxiliary unit from the outlet.
3. Disconnect the cord from the jack labeled AUX POWER INPUT
power supply.
4. Remove the auxiliary power unit (with the two cords still attached).
5.
Mount the replacement auxiliary power unit in place of the old one.
Power Supply Problems
the
on
4-9