IBM pSeries 690 Service Manual page 294

Step 152j-52
Are all the green "power good out" LEDs of both I/O subsystem DCAs off?
Yes Go to "Step 152j-53".
No Call for support.
Step 152j-53
Replace the parts in the following list one at a time and in the order listed:
v I/O subsystem backplane at P1
v I/O subsystem backplane at P2
Step 152j-54
Turn on the power.
Step 152j-55
Did the system stop with the same error code as recorded in "Step 152j-1" on page 267?
Yes Go to "Step 152j-56".
No The part just replaced is defective. Replace it. This ends the procedure.
Return the system to its original configuration.
Go to "MAP 0410: Repair Checkout" in the RS/6000 and Eserver pSeries Diagnostic Information
for Multiple Bus Systems.
Step 152j-56
Turn off the power.
Make sure all the green "power good out" LEDs of both I/O subsystem DCAs are off.
Step 152j-57
Have all the cards listed in "Step 152j-53" been replaced with new or original cards?
Yes Call for support.
No Go to "Step 152j-53".
274 Eserver pSeries 690 Service Guide