How to Isolate and Correct DIMM ECC Errors

If the ILOM reports an ECC error or a problem with a DIMM, first complete the steps in the following procedure.

In this example, ILOM reports an error with the DIMM in CPU0, slot 1. The fault LEDs on CPU0, slots 1 and 0, are lit.

Refer to Using the ILOM to Monitor the Hostfor information on locating component errors.

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Caution - Before handling components, attach an antistatic wrist strap to a chassis ground (any unpainted metal surface). The system’s printed circuit boards and hard disk drives contain components that are extremely sensitive to static electricity.

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1. If you have not already done so, shut down your server to standby power mode and remove the cover.

   Refer to the Sun Fire X4640 Server Service Manual.

2. Inspect the CPU fault LEDs for each CPU module. The CPU fault LED will be lit on the CPU module that has the faulty DIMM.
3. Disconnect the AC power cords from the server.
4. Remove the CPU module that has the DIMM problem.

   Refer to the Sun Fire X4640 Server Service Manual.

5. Inspect the installed DIMMs to ensure that they comply with the DIMM Population Rules in the Sun Fire X4640 Server Service Manual.
6. Press the Fault Remind button on the CPU module to light the faulty DIMM LEDs.

   See DIMM Fault LEDs for the location of the Fault Remind button and DIMM fault LEDs.

7. Inspect the fault LEDs on the DIMM slot ejectors.

   If any of these LEDs are lit, they can indicate the component with the fault.

8. Remove the DIMMs from the CPU module.

   Refer to the Sun Fire X4640 Server Service Manual.

9. Visually inspect the DIMMs for physical damage, dust, or any other contamination on the connector or circuits.
10. Visually inspect the DIMM slot for physical damage. Look for cracked or broken plastic on the slot.
11. Dust off the DIMMs, clean the contacts, and reseat them.
12. If there is no obvious damage, exchange the individual DIMMs between the two slots of a given pair. Ensure that they are inserted correctly with ejector latches secured. Using the slot numbers from the example:
    1. Remove the DIMMs from CPU0, slots 1 and 0.
    2. Reinstall the DIMM from slot 1 into slot 0.
    3. Reinstall the DIMM from slot 0 into slot 1.
13. Reinstall the CPU module that has the DIMM problem.

    Refer to the Sun Fire X4640 Server Service Manual.

14. Reconnect AC power cords to the server.
15. Power on the server and run the diagnostics test again.
16. Review the log file.

    • If the error now appears in CPU0, slot 0 (the opposite of the original error in slot 1), the problem is related to the individual DIMM. In this case, return both DIMMs (the pair) to the Support Center for replacement.

    • If the error still appears in CPU0, slot 1 (as the original error did), the problem is not related to an individual DIMM. Instead, it might be caused by CPU0 or by the DIMM slot. Continue with the rest of the procedure.

17. Shut down the server again and disconnect the AC power cords.
18. Remove the CPU module that has the DIMM problem, and remove another CPU module that does not indicate a DIMM problem.

    Refer to the Sun Fire X4640 Server Service Manual.

19. Remove both DIMMs of the pair and install them into paired slots on the second CPU module that did not indicate a DIMM problem.

    Using the slot numbers in the example, install the two DIMMs from CPU0, slots 1 and 0 into CPU1, slots 1 and 0 or CPU1, slots 3 and 2.

20. Reinstall both CPU modules that you removed.

    Refer to the Sun Fire X4640 Server Service Manual.

21. Reconnect AC power cords to the server.
22. Power on the server and run the diagnostics test again.
23. Review the log file.

    • If the error now appears under the CPU that manages the DIMM slots you just installed, the problem is with the DIMMs. Return both DIMMs (the pair) to the Support Center for replacement.

    • If the error remains with the original CPU, there is a problem with that CPU module.