Cannot power off system or SPCN-controlled I/O expansion unit

Use this procedure to analyze a failure of the normal command and control panel procedures to power off the system unit or an SPCN-controlled I/O expansion unit.

Attention: To prevent loss of data, ask the customer to verify that no interactive jobs are running before you perform this procedure.

Please see Power isolation procedures for important safety information before continuing with this procedure.

Is the power off problem on the system unit?
- No: Continue with the next step.
- Yes: Go to step 3.
Ensure that the SPCN cables that connect the units are connected and seated correctly at both ends. Does the unit power off, and is the power indicator light blinking slowly?
- Yes: This ends the procedure.
- No: Go to step 7.
Attempt to power off the system. Does the system unit power off, and is the power indicator light blinking slowly?
- No: Continue with the next step.
- Yes: The system is not responding to normal power off procedures which could indicate a Licensed Internal Code problem. Contact your next level of support.This ends the procedure.
Attempt to power off the system using ASMI. Does the system power off?
- Yes: The system is not responding to normal power off procedures which could indicate a Licensed Internal Code problem. Contact your next level of support.This ends the procedure.
- No: Continue with the next step.
Attempt to power off the system using the control panel power button. Does the system power off?
- Yes: Continue with the next step.
- No: Go to step 10.
Is there a reference code logged in either ASMI, the control panel or the HMC that indicates a power problem?
- Yes: Perform problem analysis for the reference code in the log.This ends the procedure.
- No: Contact your next level of support. This ends the procedure.
Is the I/O expansion unit that will not power off part of a shared I/O tower loop?
- Yes: Go to step 9.
- No: Continue with the next step.
Attempt to power off the I/O expansion unit. Were you able to power off the expansion unit?
- Yes: This ends the procedure.
- No: Go to step 10.
The unit will only power off under certain conditions:
- If the unit is in private mode, it should power off with the system unit that is connected by the SPCN frame-to-frame cable.
- If the unit is in switchable mode, it should power off if the "owning" system is powered off or is powering off, and the system unit that is connected by the SPCN frame-to-frame cable is powered off or is powering off.
Does the I/O expansion unit power off?
- No: Continue with the next step.
- Yes: This ends the procedure.
Ensure there are no jobs running on the system or partition, and verify that uninterruptible power supply (UPS) is not powering the system or I/O expansion unit. Then continue with the next step.
Perform the following:
1. Remove the system or I/O expansion unit ac power cord from the external UPS or, if an external UPS is not installed, from the customer's ac power outlet. If the system or I/O expansion unit has more than one ac line cord, disconnect all the ac line cords.
2. Exchange the following FRUs one at a time.
  If the system unit is failing:
  1. Power supply
  2. I/O backplane
  3. System control panel
  If an I/O expansion unit is failing:
  1. Each power supply
  2. I/O backplane
  3. I/O backplane in the unit preceding the unit that will not power off
  4. SPCN frame-to-frame cable
  This ends the procedure.