User Manual

ADCP-75-158 • Preliminary Issue A • June 2003 • Section 5: Maintenance
Page 5-10
© 2003, ADC Telecommunications, Inc.
3.3 LPA Troubleshooting
During normal LPA operation, the STATUS LED should be blinking green (normal operation)
or blinking yellow (minor fault).
Table 5-9. LPA Fault Isolation and Troubleshooting
LED: STATUS Color: Green Alarm Type: None
PROBLEM: The LPA is in the forced shutdown state.
POSSIBLE CAUSES
1.The MUTE/NORM/RESET switch is in the
MUTE position.
2. The Digivance system is in the STANDBY
mode.
1. Place MUTE/NORM/RESET switch in the
NORM position.
2. Use EMS to change Digivance system from
standby mode to the normal mode.
LED: STATUS Color: Yellow (blinking) Alarm Type: Minor
PROBLEM: The LPA detects a minor fault.
POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS
1. The LPA fan has failed but unit not overheated. 1. Replace LPA fan. (see Section 5.5)
LED: STATUS Color: Red Alarm Type: Major
PROBLEM: The LPA is in the internal shutdown state.
POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS
1. The interface cable between the LPA and STM
is faulty, the antenna cable is faulty, the
antenna or antenna system is faulty, or the
STM duplexer is faulty (VSWR alarm).
2. The power level of the RF forward path
composite input signal at the HU is too high.
(Over power alarm)
3 The LPA fan has failed and unit has
overheated. (High temp alarm)
4. Air intake or exhaust opening to RU outdoor
cabinet is blocked causing unit to overheat.
(High temp alarm)
5. RU ambient temperature > 50º C/122º F. (High
temp alarm)
6. The LPA is faulty. (VSWR, DC fail, Loop fail,
or low power alarm)
1. Inspect cable, antenna, and connectors and repair
or replace if faulty. Replace STM if duplexer is
faulty. To reset, use EMS to place Digivance
system in standby mode and then place system
back in normal mode.
2. 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.
3. Replace LPA fan. (see Section 5.5). To reset, use
EMS to place Digivance system in standby mode
and then place system back in normal mode.
4. Remove cause of air-flow blockage. To reset, use
EMS to place Digivance system in standby mode
and then place system back in normal mode.
5. Reduce RU ambient temperature. To reset, use
EMS to place Digivance system in standby mode
and then place system back in normal mode.
6. Replace LPA.