User's Manual

Lucent Technologies — Proprietary
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22-36
401-660-100 Issue 11 August 2000
Linear Amplifier Circuit (LAC) Maintenance
Linearizer Fan
Symptoms:
C-Series LACs:
1. Major Alarm
2. LAC LEDS = FANS and LINEARIZER
A/B-Series LACs:
1. Minor Alarm
2. LAC LEDS = LINEARIZER
Procedure:
1. Check the LINEARIZER FAN fuse on the front panel of the linearizer.
Replace with a new fuse, if blown.
2. If the fuse is good, remove the front grille from the Linearizer and carefully
check to see if the fan is turning. The fan is located on the far right side of
the linearizer cabinet. Check the fan for blockage.
3. Check the fan wiring for shorts or opens. If none are found, replace the fan
(see Section 4).
LAU Fan
Symptoms:
C-Series LACs:
1. Major Alarm
2. LAC LEDS = FANS and LAU
A/B-Series LACs:
1. Minor Alarm
2. LAC LEDS = LAU
Procedure:
1. Check the LINEAR AMPLIFIER UNIT FAN fuse on the front panel of the
Linearizer. Replace it with a new fuse, if blown.
2. If the fuse is good, check to see if the fan is turning. Check for blockage.
Remove a few LAMs at the top of the LAU and check the DC voltage at the
inductor terminals. If the voltage is greater than 22V, replace the fan. If the
voltage is less than 22V, check the DC power cabling.