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Memory problems

See this section to resolve issues related to memory.

Common memory problems​

Multiple memory modules in a channel identified as failing​

Note
Each time you install or remove a memory module, you must disconnect the server from the power source; then, wait 10 seconds before restarting the server.

Complete the following procedure to solve the problem.

  1. Reseat the memory modules; then, restart the server.
  2. Remove the highest-numbered memory module of those that are identified and replace it with an identical known good memory module; then, restart the server. Repeat as necessary. If the failures continue after all identified memory modules are replaced, go to step 4.
  3. Return the removed memory modules, one at a time, to their original connectors, restarting the server after each memory module, until a memory module fails. Replace each failing memory module with an identical known good memory module, restarting the server after each memory module replacement. Repeat step 3 until you have tested all removed memory modules.
  4. Replace the highest-numbered memory module of those identified; then, restart the server. Repeat as necessary.
  5. Reverse the memory modules between the channels (of the same processor), and then restart the server. If the problem is related to a memory module, replace the failing memory module.
  6. (Trained technician only) Install the failing memory module into a memory module connector for processor 2 (if installed) to verify that the problem is not the processor or the memory module connector.
  7. (Trained technician only) Replace the system board.

Displayed system memory is less than installed physical memory​

Complete the following procedure to solve the problem.

Note
Each time you install or remove a memory module, you must disconnect the server from the power source; then, wait 10 seconds before restarting the server.
  1. Make sure that:

    • No error LEDs are lit. See Troubleshooting by system LEDs and diagnostics display.

    • No memory module error LEDs are lit on the system board.

    • Memory mirrored channel does not account for the discrepancy.

    • The memory modules are seated correctly.

    • You have installed the correct type of memory module (see Memory module installation rules and order for requirements).

    • After changing or replacing a memory module, memory configuration is updated accordingly in the Setup Utility.

    • All banks of memory are enabled. The server might have automatically disabled a memory bank when it detected a problem, or a memory bank might have been manually disabled.

    • There is no memory mismatch when the server is at the minimum memory configuration.

  2. Reseat the memory modules, and then restart the server.

  3. Check the POST error log:

    • If a memory module was disabled by a systems-management interrupt (SMI), replace the memory module.

    • If a memory module was disabled by the user or by POST, reseat the memory module; then, run the Setup Utility and enable the memory module.

  4. Run memory diagnostics. When you start a solution and press the key according to the on-screen instructions, the LXPM interface is displayed by default. (For more information, see the “Startup” section in the LXPM documentation compatible with your server at Lenovo XClarity Provisioning Manager portal page.) You can perform memory diagnostics with this interface. From the Diagnostic page, go to Run Diagnostic > Memory test > Advanced Memory Test.

  5. Reverse the modules between the channels (of the same processor), and then restart the server. If the problem is related to a memory module, replace the failing memory module.

  6. Re-enable all memory modules using the Setup Utility, and then restart the server.

  7. (Trained technician only) Install the failing memory module into a memory module connector for processor 2 (if installed) to verify that the problem is not the processor or the memory module connector.

  8. (Trained technician only) Replace the system board.

Invalid memory population detected​

If this warning message appears, complete the following steps:
  • Invalid memory population (unsupported DIMM population) detected. Please verify memory configuration is valid.
  1. See Memory module installation rules and order to make sure the present memory module population sequence is supported.
  2. If the present sequence is indeed supported, see if any of the modules is displayed as “disabled” in Setup Utility.
  3. Reseat the module that is displayed as “disabled,” and reboot the system.
  4. If the problem persists, replace the memory module.