User Manual

ADCP-75-126 • Issue B • April 2002 • Section 5: Maintenance
Page 5-10
© 2002, ADC Telecommunications, Inc.
Alarm Type LED Color
Major STM Red
PROBLEM: Internal fault detected in STM.
POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS
1. HU and STM band mismatch.
2. The STM has failed.
1. Replace HU or STM with correct unit.
2. Replace the STM.
Alarm Type LED Color
Major PA Red
PROBLEM: Internal fault detected in LPA.
POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS
1. The LPA has failed. 1. Replace the LPA.
Alarm Type LED Color
Major VSWR Red
PROBLEM: The forward path VSWR is above the threshold.
POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS
1. Faulty antenna. 1. Check the antenna circuit for shorts or opens
(including lightning protector).
Alarm Type LED Color
Major PORT 1/PORT 2 Red
PROBLEM: No forward path optical signal is received or excessive errors are detected.
POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS
1. Faulty forward path optical link.
2. Faulty optical transmit port at the STM or
faulty optical receive port at the HU.
1. Test optical link. 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).
Alarm Type LED Color
Minor PORT 3 Yellow
PROBLEM: No diversity reverse path optical signal is received by the HU or excessive errors are detected.
POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS
1. Faulty diversity reverse path optical link.
2. Faulty optical transmit port at the STM or
faulty optical receive port at the HU.
1. Test optical link. 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).
Alarm Type LED Color
Major FAIL Yellow
PROBLEM: Internal fault detected in the LPA.
POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS
1.The LPA has failed. 1. Replace LPA
Table 5-8. STM and LPA Fault Isolation and Troubleshooting, continued