User's Manual

ADCP-75-187 • Preliminary Issue 1B • November 2005 • Section 4: MAINTENANCE
Page 4-9
© 2005, ADC Telecommunications, Inc.
Table 4-6. Remote Unit Fault/Alarm Corrective Action
PROBLEM A: The RU (STM or LPA) is overheating.
POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS
1. Debris preventing air from freely circulating
around the RU aluminum enclosure.
2. Ambient temperature > 50º C/122º F.
3. The RU has failed.
1. Remove cause of air-flow blockage.
2. Reduce ambient temperature.
3. Replace RU.
PROBLEM B: The output power from the LPA exceeds the maximum rating.
POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS
1. The power level of the RF forward path
composite input signal at the HU is too high.
2. The RU (LPA) has failed.
1. Check the power level of the RF composite input
signal at the HU and adjust to correct level. To
reset, use EMS to place Digivance system in
standby mode and then place system back in
normal mode.
2. Replace RU.
PROBLEM C: The VSWR at the LPA exceeds the threshold setting of 3:1.
POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS
1. The antenna cable or antenna cable connectors
are faulty.
2. The antenna or antenna system is faulty.
3.The RU qudraplexer or LPA has failed.
1. Inspect antenna cable and connectors and repair
or replace as needed.To reset, use EMS to place
Digivance system in standby mode and then place
system back in normal mode.
2. Check the antenna circuit for shorts or opens
(including lightning protector). To reset, use EMS
to place Digivance system in standby mode and
then place system back in normal mode.
3. Replace RU.
Remote Unit LED Software Fault/Status Indicator Corrective Action
or Reference
Host Lost - The STM cannot
communicate with Host (HU)
EMS Link Status - The EMS cannot
communicate with STM
RF Power - No RF power detected
at quadraplexer (STM)
LPA Disable - The LPA is shut down
No Associated LED
See Table 4-6
Problem G
See Table 4-6
Problem F
See Table 4-6
Problem E
See Table 4-6
Problem H
Table 4-5. Remote Unit Fault/Alarm Isolation Diagram, continued
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