Lenovo 6528 - Manual (Page 149)

Memory problems
v Follow the suggested actions in the order in which they are listed in the Action column until the problem
is solved.
v See the parts listing in the Hardware Maintenance Manual to determine which components are customer
replaceable units (CRUs) and which components are field replaceable units (FRUs).
v If an action step is preceded by “(Trained service technician only),” that step must be performed only by a
trained service technician.
Symptom Action
The amount of system memory
that is displayed is less than the
amount of installed physical
memory. 1. Make sure that:
v No error LEDs are lit on the operator information panel or on the DIMM.
v Memory mirroring does not account for the discrepancy.
v The memory modules are seated correctly.
v You have installed the correct type of memory.
v If you changed the memory, you updated the memory configuration in the
Setup Utility.
v 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.
2. Check the POST event log for DIMM error messages:
v If a DIMM was disabled by a systems-management interrupt (SMI), replace
the DIMM.
v If a DIMM was disabled by the user or by POST, run the Setup Utility and
enable the DIMM.
3. Run memory diagnostics (see ″Diagnostic programs, messages, and error
codes ″ in the Hardware Maintenance Manual).
4. Make sure that there is no memory mismatch when the server is at the
minimum memory configuration (two 512 MB DIMMs; see the information about
the minimum required configuration on page “Solving undetermined problems”
on page 142).
5. Add one pair of DIMMs at a time, making sure that the DIMMs in each pair are
matching.
6. Reseat the DIMMs.
7. Replace the DIMMs in step 6, one at a time, in the order shown, restarting the
server each time.
Multiple rows of DIMMs in a
branch are identified as failing. 1. Reseat the DIMMs; then, restart the server.
2. Replace the lowest-numbered DIMMs with identical known good DIMMs; then,
restart the server. Repeat as necessary. If the failures continue after all
identified pairs are replaced, go to step4.
3. 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 in the
failed pair with an identical known good DIMM, restarting the server after you
reinstall each DIMM. Replace the failed DIMM. Repeat step 3 until you have
tested all removed DIMMs.
4. (Trained service technician only) Replace the system board.
Chapter 8. Troubleshooting 133