User Manual

ADCP-75-150 • Preliminary Issue A • March 2003 • Section 5: Maintenance
Page 5-8
© 2003, ADC Telecommunications, Inc.
During normal STM operation, all LED’s should be green except the STANDBY LED which
should be Off. When a Minor alarm occurs, one or more of the LED’s will turn yellow. When a
Major alarm occurs, one or more of the LED’s will turn red.
It is recommended that whenever there are multiple alarms, the optical alarms should be
checked and cleared first. Because the host and remote units function as a system, a fault in the
fiber optic link will cause various unit alarms to be reported.
Table 5-8. STM Fault Isolation and Troubleshooting
LED: AC POWER Color: Off Alarm Type: Major
PROBLEM: 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.
LED: STANDBY Color: Green (blinking) or
Yellow (blinking)
Alarm Type: None
PROBLEM: The RU is out of service.
POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS
1. The RU is in the standby (green) or program
load (yellow) mode.
1. Use DEMS to place the RU in the normal (off)
mode.
LED: HOST UNIT Color: Yellow Alarm Type: Minor
Problem: A minor alarm fault is detected at the HU.
POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS
1. The HU is overheating. 1. Check HU LED indicators and refer to Table 5-7
LED: HOST UNIT Color: Red Alarm Type: Major
PROBLEM: A major alarm fault is detected at the HU.
POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS
1. Fiber optic link fault.
2. The HU is not powered.
3. The HU has failed.
1. Check HU LED indicators and refer to Table 5-7.
2. Check HU LED indicators and refer to Table 5-7.
3. Check HU LED indicators and refer to Table 5-7.
LED: STM Color: Yellow Alarm: Minor
PROBLEM: 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.
1. Remove cause of air-flow blockage.
2. Reduce ambient temperature.
3. Replace STM fan (See Section 5.4).