User Manual

ADCP-75-126 • Issue B • April 2002 • Section 5: Maintenance
Page 5-8
© 2002, ADC Telecommunications, Inc.
Alarm Type LED Color
Major HOST UNIT Red
PROBLEM: Internal fault detected in HU.
POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS
1. HU and STM band mismatch.
2. The HU has failed.
1. Replace HU or STM with correct unit.
2. Replace the HU.
Alarm Type LED Color
Major REMOTE UNIT Red
PROBLEM: A major alarm is detected at the RU.
POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS
1. The STM or LPA has failed, the STM is not
receiving a forward path optical signal, or the
RU cabinet door is open.
1. Check RU for alarms and refer to Table 5-8.
Alarm Type LED Color
Major DRIVE Red
PROBLEM: The RF signal is above the overdrive threshold.
POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS
1. Incorrect attenuation in forward path RF
coaxial link.
1. Check Forward Attenuator setting and adjust if
attenuation is too low.
Alarm Type LED Color
Major PORT 1/PORT 2 Red
PROBLEM: No reverse path optical signal is received or excessive errors are detected.
POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS
1. Faulty reverse path optical link.
2. Faulty optical transmit port at the HU or faulty
optical receive port at the STM.
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 or excessive errors are detected.
POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS
1. Faulty diversity reverse path optical link.
2. Faulty optical transmit port at the HU or faulty
optical receive port at the STM.
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).
Table 5-7. Host Unit Fault Isolation and Troubleshooting, continued