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,” on page 153 to check if a component is a consumable, structural, or FRU part.v If an action step is preceded by “(Trained technician only),” that step must be performed only by a trainedtechnician.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.1. Make sure that:v No error LEDs are lit on the operator information panel, on the memorytray, or on the MAX5 memory expansion module.v Memory mirroring does not account for the discrepancy.v The memory modules are seated correctly (see “Removing a memorymodule” on page 186 and “Replacing a memory module” on page 187).v You have installed the correct type of memory.v If you changed the memory, you updated the memory configuration in theSetup utility.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.2. 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.3. Run memory diagnostics (see “Running the DSA Preboot diagnostic programs”on page 129).4. Make sure that there is no memory mismatch when the server is at theminimum memory configuration ( see “Memory module installation” on page60 for information about DIMM rules and population sequence).5. Reseat the DIMM.6. Restart the server.Multiple rows of DIMMs in abranch are identified as failing. 1. Reseat the DIMMs; then, restart the server.1. Remove the lowest-numbered DIMM pair of those that are identified andreplace it with an identical pair of known good DIMMs; then, restart theserver. Repeat as necessary. If the failures continue after all identified pairs arereplaced, go to step 4.2. Return the removed DIMMs, one pair at a time, to their original connectors,restarting the server after each pair, until a pair fails. Replace each DIMM inthe failed pair with an identical known good DIMM, restarting the server aftereach DIMM. Replace the failed DIMM. Repeat step 3 until you have tested allremoved DIMMs.3. Replace the lowest-numbered DIMM pair of those identified; then, restart theserver. Repeat as necessary.4. (Trained technician only) Replace the system board.Chapter 4. Troubleshooting 137
