Memory problemsUse this information to solve memory problems.Table 44. Symptoms and user actions for memory problemsv Follow the suggested actions in the order in which they are listed in the Action column until the problem issolved.v See Chapter 5, “Parts listing, System x3850 X6 and x3950 X6 Types 3837 and 3839,” on page 205 to determinewhich components are customer replaceable units (CRU) and which components are field replaceable units(FRU).v If an action step is preceded by (Trained service technician only), that step must be performed only by a Trainedservice technician.Symptom ActionThe amount of system memorythat is displayed is less than theamount of installed physicalmemory.Note: If you change memory, you must update the memory configuration in theSetup utility (see “Using the Setup utility” on page 126 for more information). Formore information about installing DIMMs and DIMM population sequence, see“Installing a memory module” on page 47, “Independent memory mode” on page55, “Lockstep memory mode” on page 59, “Memory mirroring” on page 53, and“Memory rank sparing” on page 54.1. If the server was recently installed, moved, or serviced, make sure that allDIMMs are seated correctly.2. If a new DIMM has been installed recently, verify that you have not receivedany configuration events in the event log. Otherwise, check the IMM event log.If any DIMM configuration events are listed, resolve the DIMM eventproblems first.3. Make sure that:v No error LEDs are lit on the operator information panel or on the computebook.v Memory mirroring does not account for the discrepancy (see “Memorymirroring” on page 53).v The memory modules are seated correctly (see “Removing a memorymodule” on page 239 and “Replacing a memory module” on page 240).v You have installed the correct type of memory (see “Installing a memorymodule” on page 47).v If you changed the memory, you updated the memory configuration in theSetup utility (see “Using the Setup utility” on page 126).v All banks of memory are enabled. The server might have automaticallydisabled a memory bank when it detected a problem, or a memory bankmight have been manually disabled.4. Check the POST event log:v If a DIMM was disabled by a systems-management interrupt (SMI), replacethe DIMM.v If a DIMM was disabled by the user or by POST, run the Setup utility andenable the DIMM.5. Run memory diagnostics (see “IBM Dynamic System Analysis” on page 173). Ifan error is detected, follow the steps to correct the error.6. Restart the server.186 System x3850 X6 and x3950 X6 Types 3837 and 3839: Installation and Service Guide
