IBM 265 Service Manual page 68

Step 1520-5
One of the cables you unplugged from the power backplane may be defective.
1. Unplug the power cables from the system.
2. Reconnect one of the cables to the power backplane.
3. Connect the power cables to the system.
Do the ac LEDs on the power supplies come on within 30 seconds after applying
ac power?
NO
YES
Step 1520-6
Either the power supplies or the power backplane may be defective.
To test each FRU, exchange the FRUs that have not already been exchanged in the
following order.
v Power supply 1.
v Power supply 2.
v Power supply 3 (if installed).
v Power backplane.
1. Turn off the power.
2. Unplug the power cables from the system.
3. Exchange one of the FRUs in the list.
4. Connect the power cables to the system.
Do the ac LEDs on the power supplies come on within 30 seconds after applying
ac power?
NO
YES
52
Service Guide
Replace the last cable that you connected to the power backplane.
Repeat this step until all the cables have been reconnected.
Replace the faulty cooling fan. Go to "MAP 0410: Repair Checkout" in the
RS/6000 Eserver pSeries Diagnostic Information for Multiple Bus Systems .
Repeat this step until the defective cable is identified or all the cables have
been reconnected.
Reinstall the original FRU.
Repeat this step until the defective FRU is identified or all the FRUs have been
exchanged.
If the symptom did not change and all the FRUs have been exchanged, call
your service support person for assistance.
Go to "MAP 0410: Repair Checkout" in the RS/6000 Eserver pSeries
Diagnostic Information for Multiple Bus Systems .