User Manual

ADCP-75-150 • Preliminary Issue A • March 2003 • Section 5: Maintenance
Page 5-9
© 2003, ADC Telecommunications, Inc.
LED: STM Color: Red Alarm Type: Major
PROBLEM: A major alarm fault detected by the STM.
POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS
1. Fiber optic link fault.
2. The HU is not powered.
3. HU and STM band mismatch.
4. The STM has failed.
1. Follow procedure specified when the PORT 1/
PORT 2 LED is red.
2. Check HU LED indicators and refer to Table 5-7
3. Replace HU or STM with correct unit.
4. Replace the STM.
LED: PA Color: Yellow Alarm Type: Minor
PROBLEM: 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 Section 5.5).
LED: PA Color: Red Alarm Type: Major
PROBLEM: A major alarm fault is detected by the LPA.
POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS
1. The STM to LPA connecting cable is faulty.
2. The LPA has failed.
3. The STM has failed.
1. Inspect cable and repair or replace if faulty.
2. Check LPA and refer to Table 5-9. Replace the
LPA if it is faulty.
3. Replace the STM.
LED: VSWR Color: Red Alarm Type: Major
PROBLEM: The forward path VSWR is above the threshold.
POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS
1. Faulty antenna or antenna system.
2. Faulty antenna cable.
3. The STM has failed.
1. Check the antenna circuit for shorts or opens
(including lightning protector).
2. Check the antenna cable for faulty connections.
3. Replace the STM.
LED: PORT 1/PORT 2 Color: Red Alarm Type: Major
PROBLEM: Excessive errors are detected in the forward path optical signal.
POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS
1. Faulty forward path optical fiber. 1. Test optical fiber. Clean connector if dirty. Repair
or replace optical fiber if faulty. (See Section 4.1).
Table 5-8. STM Fault Isolation and Troubleshooting, continued