PWR1905

Refer to Power isolation procedures for important safety information before servicing the system.

Instructions for Model 8203-E4A

1. Is the reference code 1xxx 1B01?
   • Yes: Continue with the next step.
   • No: This procedure only isolates problems that cause 1xxx 1B01 to be logged. Return to the procedure that sent you here. This ends the procedure.
2. Perform the following:
   1. Power off the system and disconnect the ac power cable from the unit you are working on.
   2. Disconnect all the I/O devices (tape, diskette, optical, and disk units) by sliding them partially out of the system unit (see Physical Locations).
   3. Remove and label all cards (for example, PCI adapters, GX adapter(s), RIO/HSL, and RAID cards if installed).
   4. Reconnect the ac power cable or cables to the unit you are working on.
   5. Power on the system (see Powering on and powering off).

   Does a power reference code occur?

   • Yes: Continue with the next step.
   • No: Go to step 5.
3. Perform the following:
   1. Power off the system.
   2. Replace one of the system fans (see Physical Locations).
   3. Power on the system (see Powering on and powering off).

   Does a power reference code occur?

   • Yes: Continue with the next step.
   • No: The fan you just replaced was the failing item. This ends the procedure.
4. Have you tried replacing all the fans?
   • Yes: Reinstall the fan you just replaced in step 3 and continue with the next step.
   • No: Perform the following:
     1. Power off the system.
     2. Reinstall the fan that you just removed in step 3 to its original location.
     3. Repeat step 3
5. Perform the following:
   1. Power off the system.
   2. Reinstall all the cards (PCI adapters, memory DIMMs, GX adapter(s), RIO/HSL and RAID cards) you removed in step 2 into their original locations.
   3. Power on the system.

   Does a power reference code occur?

   • Yes: Continue with the next step.
   • No: Go to step 8.
6. Perform the following:
   1. Power off the system.
   2. Disconnect one of the cards you reinstalled in step 5.
   3. Power on the system.

   Does a power reference code occur?

   • Yes: Continue with the next step.
   • No: Exchange the last card you disconnected in this step (see Physical Locations). This ends the procedure.
7. Have you disconnected all the cards?
   • No: Repeat step 6.
   • Yes: Reinstall all of the parts removed or exchanged in this procedure and return to Starting a Service Call. This ends the procedure.
8. Perform the following:
   1. Power off the system.
   2. Reconnect all of the I/O devices (tape, diskette, optical, and disk units) that you disconnected in step 2.
   3. Power on the system.

   Does a power reference code occur?

   • Yes: Continue with the next step.
   • No: The problem has been resolved. This ends the procedure.
9. Perform the following:
   1. Power off the system.
   2. Disconnect one of the I/O devices (tape, diskette, optical, and disk units) that you reconnected in step 8.
   3. Power on the system.

   Does a power reference code occur?

   • Yes: Continue with the next step.
   • No: Exchange the last I/O device you disconnected in this step (see Physical Locations). This ends the procedure.
10. Have you tried disconnecting all of the I/O devices?
    • No: Repeat step 9.
    • Yes: Continue with the next step.
11. Replace the system backplane (Un-P1). Reinstall all of the parts you have removed or exchanged in this procedure. This ends the procedure.