Memory Problems - Lenovo ThinkServer RD240 Hardware Maintenance Manual

Memory problems

• Follow the suggested actions in the order in which they are listed in the Action column until the problem is
solved.
• See the parts listing in Chapter 6 "Parts listing, RD240 Types 1045, 1046, 1047, and 1048" on page 89 to
determine which components are customer replaceable units (CRUs) and which components are field
replaceable units (FRUs).
• If an action step is preceded by "(Trained service technician only)," that step must be performed only by
a trained service technician.
Symptom
The amount of system memory
that is displayed is less than
the amount of installed physical
memory.
Multiple rows of DIMMs in a
branch are identified as failing.
Action
1. Make sure that:
• No error LEDs are lit on the operator information panel or on the DIMM.
• Memory mirroring does not account for the discrepancy.
• The memory modules are seated correctly.
• You have installed the correct type of memory.
• If you changed the memory, you updated the memory configuration in the
Setup Utility program.
• 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:
• 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 program
and enable the DIMM.
3. Make sure that there is no memory mismatch when the server is at the minimum
memory configuration.
4. Add one pair of DIMMs at a time, making sure that the DIMMs in each pair
are matching.
5. Reseat the DIMMs.
6. Replace the DIMMs in step 5 on page 15, one at a time, in the order shown,
restarting the server each time.
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 step 4 on page 15.
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 on page 15 until
you have tested all removed DIMMs.
4. (Trained service technician only) Replace the system board.
15
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Chapter 3 Diagnostics