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Memory problems

Use this information to solve memory problems.

Table 1. Memory problems.

A table with one spanned column at the top and two additional columns with headers. This table provides information about symptoms and user actions to solve memory 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, Lenovo System x3750 M4 Type 8753 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.
SymptomAction
The amount of system memory that is displayed is less than the amount of installed physical memory.
Note
If you change memory, you must update the memory configuration in the Setup utility (see Using the Setup utility for more information). For more information about installing DIMMs, see Installing a memory module, Non-mirroring (independent mode), Memory mirroring, and Memory sparing.
  1. If the server was recently installed, moved, or serviced, make sure that all DIMMs are seated correctly.
  2. If a new DIMM has been installed recently, verify that you have not received any configuration events in the event log. Otherwise, check the IMM2 event log. If any DIMM configuration events are listed, resolve the event problems first.
  3. Make sure that the following conditions are met:
    • No error LEDs are lit on the operator information panel or on the microprocessor and memory expansion tray.
    • Memory mirroring does not account for the discrepancy (see Memory mirroring).
    • The memory modules are seated correctly (see Removing a memory module and Replacing a memory module).
    • You have installed the correct type of memory (see Installing a memory module).
    • If you changed the memory, you updated the memory configuration 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.
  4. Check the POST event log:
    • If a DIMM was disabled by a systems-management interrupt (SMI), replace the DIMM.
    • If a DIMM was disabled by the user or by POST, run the Setup utility and enable the DIMM.
  5. Run memory diagnostics (see Dynamic System Analysis). If an error is detected, follow the steps to correct the error.
  6. For the system board and the microprocessor and memory expansion tray, add DIMMs one at a time (see Replacing a memory module).
  7. Reseat the DIMM.
  8. Restart the server.
Multiple rows of DIMMs in a branch are identified as failing.
  1. Check the system-event log for any events associated with a failing DIMM.
  2. Resolve the DIMM errors that are listed in the system-event log, starting with the first error that has occurred.
  3. Resolve any DIMM configuration mismatches that are listed in the IMM event log.