Power problems

Use this information to solve power problems.

  • Follow the suggested actions in the order in which they are listed in the Action column until the problem is solved.
  • See Parts listing, IBM System x3550 M3 Type 4254 and 7944 to determine which components are customer replaceable units (CRU) and which components are field replaceable units (FRU).
  • If an action step is preceded by "(Trained service technician only)," that step must be performed only by a Trained service technician.
  • Go to the IBM support website at IBM Support Portal to check for technical information, hints, tips, and new device drivers or to submit a request for information.
Symptom Action
The power-control button does not work, and the reset button does work (the server does not start).
Note: The power-control button will not function until approximately 20 to 40 seconds after the server has been connected to power.
  1. Make sure that the power-control button is working correctly:
    1. Disconnect the server power cords.
    2. Reconnect the power cords.
    3. (Trained service technician only) Reseat the operator information panel cables, and then repeat steps 1a and 1b.
      • (Trained service technician only) If the server starts, reseat the operator information panel. If the problem remains, replace the operator information panel.
      • If the server does not start, bypass the power-control button by using the force power-on jumper (see System-board switches and jumpers). If the server starts, reseat the operator information panel. If the problem remains, replace the operator information panel.
  2. Make sure that the reset button is working correctly:
    1. Disconnect the server power cords.
    2. Reconnect the power cords.
    3. (Trained service technician only) Reseat the light path diagnostics panel cable, and then repeat steps 1a and 1b.
      • (Trained service technician only) If the server starts, replace the light path diagnostics panel.
      • If the server does not start, go to step 3.
  3. Make sure that both power supplies installed in the server are of the same type. Mixing different power supplies in the server will cause a system error (the system-error LED on the front panel turns on and the PS and CNFG LEDs on the operator information panel are lit).
  4. Make sure that:
    • The power cords are correctly connected to the server and to a working electrical outlet.
    • The type of memory that is installed is correct.
    • The DIMMs are fully seated.
    • The LEDs on the power supply do not indicate a problem.
    • The microprocessors are installed in the correct sequence.
  5. Reseat the following components:
    1. DIMMs
    2. Power supplies
    3. (Trained service technician only) Power switch connector
  6. Replace the components listed in step 5 one at a time, in the order shown, restarting the server each time.
  7. If you just installed an optional device, remove it, and restart the server. If the server now starts, you might have installed more devices than the power supply supports.
  8. See Power-supply LEDs and Solving undetermined problems.
The OVER SPEC LED on the light path diagnostics panel is lit, and the 12v channel A LED on the system board is lit.
  1. Turn off the server and disconnect the power from the server.
  2. Remove the optical drive, fans, hard disk drives, and hard disk drive backplane.
  3. Restart the server to see whether the problem remains.
  4. Reinstall each device that you removed in step 2 one at a time, starting the server each time, to isolate the failing device.
  5. Replace any failing device.
  6. (Trained service technician only) Replace the system board.
The OVER SPEC LED on the light path diagnostics panel is lit, and the 12v channel B LED on the system board is lit.
  1. Turn off the server and disconnect the power from the server.
  2. Remove the PCI riser card in connector 1, all DIMMs, and the microprocessor in socket 2.
  3. Restart the server to see whether the problem remains.
  4. Reinstall each device that you removed in step 2 one at a time, starting the server each time, to isolate the failing device.
  5. Replace any failing device.
  6. (Trained service technician only) Replace the system board.
The OVER SPEC LED on the light path diagnostics panel is lit, and the 12v channel C LED on the system board is lit.
  1. Turn off the server and disconnect the power from the server.
  2. Remove the SAS/SATA RAID riser card, DIMMs in connectors 1 through 9, and the microprocessor in socket 1.
    Note: The server will not power-on when the microprocessor in socket 1 or 2 is not installed in the server. (Trained service technician only) Toggle the switch block (SW4), switch 3 to allow the server to power-on. See System-board switches and jumpers for the location of the SW4 switch block on the system board.
  3. Restart the server to see whether the problem remains.
  4. Reinstall each device that you removed in step 2 one at a time, starting the server each time, to isolate the failing device.
  5. Replace any failing device.
  6. (Trained service technician only) Replace the system board.
The OVER SPEC LED on the light path diagnostics panel is lit, and the 12v channel D LED on the system board is lit.
  1. Turn off the server and disconnect the power from the server.
  2. (Trained service technician only) Remove the microprocessor in socket 1.
    Note: The server will not power-on when the microprocessor in socket 1 or 2 is not installed in the server. (Trained service technician only) Toggle the switch block (SW4), switch 3 to allow the server to power-on. See System-board switches and jumpers for the location of the SW4 switch block on the system board.
  3. Restart the server to see whether the problem remains.
  4. (Trained service technician only) Reinstall the microprocessor in socket 1 and restart the server.
  5. Replace any failing device.
  6. (Trained service technician only) Replace the system board.
The OVER SPEC LED on the light path diagnostics panel is lit, and the 12v channel E LED on the system board is lit.
  1. Turn off the server and disconnect the power from the server.
  2. Remove the PCI riser card from PCI riser connector 2 and the microprocessor in socket 2.
  3. Restart the server to see whether the problem remains.
  4. Reinstall each device that you removed in step 2 one at a time, starting the server each time, to isolate the failing device.
  5. Replace any failing device.
  6. (Trained service technician only) Replace the system board.
The OVER SPEC LED on the light path diagnostics panel is lit, and the 12v channel AUX LED on the system board is lit.
  1. Turn off the server and disconnect the power from the server.
  2. Remove all PCI Express and PCI-X cards, all PCI riser cards, the operator information panel, and the Ethernet adapter (if installed).
    Note: The server will not power-on when the microprocessor in socket 1 or 2 is not installed in the server. (Trained service technician only) Toggle the switch block (SW4), switch 3 to allow the server to power-on. See System-board switches and jumpers for the location of the SW4 switch block on the system board.
  3. Restart the server to see whether the problem remains.
  4. Reinstall each device that was removed in step 2 one at a time, starting the server each time, to isolate the failing device.
  5. Replace any failing device.
  6. (Trained service technician only) Replace the system board.
The server does not turn off.
  1. Determine whether you are using an Advanced Configuration and Power Interface (ACPI) or a non-ACPI operating system. If you are using a non-ACPI operating system, complete the following steps:
    1. Press Ctrl+Alt+Delete.
    2. Turn off the server by pressing the power-control button and hold it down for 5 seconds.
    3. Restart the server.
    4. If the server fails POST and the power-control button does not work, disconnect the power cord for 20 seconds; then, reconnect the power cord and restart the server.
  2. If the problem remains or if you are using an ACPI-aware operating system, suspect the system board.
The server unexpectedly shuts down, and the LEDs on the operator information panel are not lit. See Solving undetermined problems.
Parent topic: Troubleshooting tables