Replacement Procedures; Troubleshooting; Fan Failure - Cisco VCO/4K Mechanical Assemblies

5.2 Replacement Procedures

Fan units can be replaced while the system continues to operate. If the unit is replaced while
the system is operating, caution must be taken to ensure that no objects can become lodged or
tangled in the fans when they begin to operate during the replacement procedure (step 3.)
To replace a fan unit:
1. Unpack the replacement fan unit. Be sure all packing materials have been removed.
2. Lift the fan unit into position so the top of the unit is flush with the top of the VCO/4K
enclosure, and guide about half-way into the system enclosure. If the unit cannot be
guided or lifted into the enclosure, make certain that the top of the unit has been
correctly positioned.
3. Connect the power supply located on the back, left side of the fan unit.
4. Continue sliding in the fan unit until the front is flush with the back of the VCO/4K
enclosure, then tighten the thumb screws located on the left and right sides of the unit.
Refer to Figure 3 for the location of the thumb screws.
NOTE: Do not force the fan unit into the cabinet, the wires may be blocking the
installment of the unit. Make certain that the fan power supply wires do not get
pinched between the fan unit and the enclosure.

6.0 TROUBLESHOOTING

If the MAJOR and AUX1 alarms are tripped by the AAC, suspect problems with the fan unit.
Check the status of the alarm indicator on the fan unit.
Refer to the VCO/4K Mechanical Assemblies: VCO/4K Power Subsystem for a guide to LED
States.

6.1 Fan Failure

If the Fan Alarm LED on a fan unit illuminates, check the following to identify and correct the
problem. These troubleshooting procedures require that the fan unit be removed from the
VCO/4K.
Refer to Section 5.0 for instructions on how to remove the fan unit.
• Check to determine if a foreign object is blocking fan rotation.
• Check that the internal connectors have not become disconnected.
• Make certain that the J5 power connector has not become disconnected.
If the failed fan does not operate, and all troubleshooting details have been checked, remove
the fan unit, pack, and ship it to Cisco Systems for service.
CAUTION: Do not operate the VCO/4K until the fan unit has been replaced.
TROUBLESHOOTING
Fan Unit 1-7