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Cisco uBR10012 Universal Broadband Router Troubleshooting Guide
OL-1237-01
Chapter 2 PEM Faults and Fan Assembly Failures
Fan Assembly Module Faults
Table 2-6 Fan Assembly Module Fault Indications and Recommended Action
Symptom Steps to Take
Fans OK LED is not lit
1. Make sure the fan assembly module is fully inserted into the chassis.
2. Place your hand in front of the fan assembly module outlet to determine if the fans are
operating. If the fans are running, remove the fan assembly module and inspect the wiring
to the LEDs and fans to ensure that the wires are not nicked or cut.
3. Make sure that two AC PEM or two DC PEM modules are installed in the chassis.
Although only one PEM is required to power the chassis, two PEMs should be installed
for proper airflow. (If one PEM fails, leave the failed module in the chassis until the
replacement module can be installed.)
4. If you use DC PEMs, make sure the wiring is not reversed.
5. Replace the fan assembly module.
SINGLE FAN FAILURE
LED is lit
One fan in the fan assembly module has failed. The fan assembly can cool the chassis
sufficiently with three working fans, but replace the failed fan as soon as possible.
MULTI-FAN FAILURE LED
is lit
More than one fan has failed, and the fan assembly cannot sufficiently cool the chassis.
Replace the failed fans immediately. If necessary, power down the chassis until replacements
are available.
Fans run but the system
overheats
1. Make sure that all intake and exhaust vents on the front and rear of the chassis are free
of blockages.
2. Make sure that the ambient temperature and other environmental factors in the system
area are within the ranges specified in the “Displaying System Environment
Information” section on page 1-4.
3. Make sure all line cards and blank faceplates are in place. Make sure two PEM modules
are installed in the chassis. The cooling system cannot operate effectively unless the
chassis is fully enclosed.
4. Check the air filter, and, if necessary, clean or replace it.
5. Reduce the ambient temperature of the area surrounding the Cisco uBR10012 chassis.
This can be done using air conditioning, using fans to circulate the air in the room, and
closing the blinds on any windows that are facing the sun.