User Manual

ADCP-75-179 • Preliminary Issue A • September 2004 • Section 4: maintenance
Page 4-12
© 2004, ADC Telecommunications, Inc.
Table 4-7. STM Fault/Alarm Corrective Action
PROBLEM A: The RU is powered by the battery back-up system.
POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS
1. The AC power system circuit breaker is open
or the AC power has failed.
2. The STM has failed.
1. Check the AC power system, repair as needed,
and reset circuit breaker.
2. Replace the STM.
PROBLEM B: The STM is overheating.
POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS
1. Air intake or exhaust opening to the remote
unit cabinet is blocked
2. Ambient temperature > 50º C/122º F.
3. Faulty fan.
4. The STM has failed.
1. Remove cause of air-flow blockage.
2. Reduce ambient temperature.
3. Replace STM fan (See applicable manual).
4. Replace STM.
PROBLEM C: The LPA is overheating.
POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS
1. Air intake or exhaust opening to the remote
unit cabinet is blocked
2. Ambient temperature > 50º C/122º F.
3. Faulty fan.
1. Remove cause of air-flow blockage.
2. Reduce ambient temperature.
3. Replace LPA fan (See applicable manual).
PROBLEM D: The forward path VSWR is above threshold.
POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS
1. Faulty antenna or antenna system.
2. Faulty antenna cable.
3. The STM qudraplexer has failed.
1. Check the antenna system for shorts or opens
(including lightning protector).
2. Check the antenna cable for faulty connections.
3. Replace the STM.
PROBLEM E: No light received over the forward path or excessive errors received over the forward path
POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS
1. Faulty forward path optical fiber.
2. Faulty optical transmit port at the HU;
or faulty optical receive port at the STM.
1. Test optical fiber. Clean connector if dirty. Repair
or replace optical fiber if faulty. (See Section 4.1).
2. Test optical ports. Replace HU or STM if port is
faulty (see Section 4.2).
PROBLEM F: The STM does not respond to control or monitoring commands sent by the EMS.
POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS
1. The cable connection between the STM and
the EMS computer is faulty.
1. Inspect EMS cable and repair or replace if faulty.
PROBLEM G: An external fault is detected at the Remote Unit.
POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS
1. The RU cabinet door is open.
2. Customer specified external fault at RU
1. Close RU cabinet door.
2. Check RU and correct specified external fault.