Memory Problems - Lenovo x3300 M4 7382 Installation And Service 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 Chapter 5 "Parts listing, Lenovo System x3300 M4 Type 7382" on page 159 to check if a component is a
structural, or FRU part.
• If an action step is preceded by "(Trained technician only)," that step must be performed only by a trained
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.
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System x3300 M4 Installation and Service Guide
Action
Note: If you change memory, you must update the memory configuration in the
Setup utility.
1. Make sure that:
• No error LEDs are lit on the operator information panel, on the memory tray,
or on the MAX5 memory expansion module.
• Memory mirroring does not account for the discrepancy.
• The memory modules are seated correctly (see "Removing a memory
module" on page 259 and "Installing a memory module" on page 45).
• You have installed the correct type of memory.
• 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.
2. 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.
3. Run memory diagnostics (see "Running the DSA Preboot diagnostic programs"
on page 130).
4. Make sure that there is no memory mismatch when the server is at the minimum
memory configuration ( see "Installing a memory module" on page 45 for
information about DIMM rules and population sequence).
5. Reseat the DIMM.
6. Restart the server.
1. Reseat the DIMMs; then, restart the server.
2. Remove the lowest-numbered DIMM pair of those that are identified and
replace it with an identical pair of known good DIMMs; then, restart the server.
Repeat as necessary. If the failures continue after all identified pairs are
replaced, go to step 4.
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 each
DIMM. Replace the failed DIMM. Repeat step 3 until you have tested all
removed DIMMs.
4. Replace the lowest-numbered DIMM pair of those identified; then, restart the
server. Repeat as necessary.
• If one DIMM fails, the user can reverse the DIMMs between the channels (of
the same microprocessor), and then restart the server. If the problem is
related to a DIMM, replace the failing DIMM.