PowerSupplies 7-11
7
7.4.3 Troubleshootinga PCM
A green LED is lit on the power supply when it is operational. When a PCM
fails, a yellow LED is lit on the power supply.
Youwill see a message similar to the following example on your system
console when a PCM fails:
See Chapter 10, “Flow Diagrams for Troubleshooting,”for more information.
7.4.4 Replacing a PCM
Caution – Remove and replace the PCM in a running system. Do not replacea
PCM while the system is in the low power mode. In the low power mode, the
front panel and board LEDs are all offwhile the yellow LEDs are lit on the
power supplies.
Replacing a PCM during low power mode will cause the system to power up
immediately and result in a severe overload condition for that PCM (the other
PCMs will remain in the low power mode).
Caution – Replace the PCM within several minutes or risk overheating the
board(s) cooled by the fans in that power supply.
Note – Remember the following rules when attempting the hot-plug
replacement of a PCM:
• The peripheral power supply is providing precharge.
• There is (power) redundancy in the system.
Use the printdiag (1M) command to determine if precharge current is
present.
When replacing a PCM, be surethat the extraction lever is on the outside edge
of the system. See Figure7-6.
WARNING: Core Power Supply 2 Failing
WARNING: Redundant power lost
!
!