IBM X3950 X5 Problem Determination And Service Manual page 64

About this task
v Follow the suggested actions in the order in which they are listed in the Action column until the problem is
solved.
v See Chapter 4, "Parts listing, Types 7145, 7146, 7143, and 7191," on page 81 to determine which 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
trained service technician.
Symptom
The amount of system memory
that is displayed is less than the
amount of installed physical
memory.
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IBM System x3850 X5 and x3950 X5 Types 7145, 7146, 7143, and 7191: Problem Determination and Service Guide
Action
Note: If you change the memory, you must update the memory configuration in
the Setup utility.
1. Make sure that:
v No error LEDs are lit on the operator information panel, the memory card,
or on the memory expansion module.
v Memory mirroring does not account for the discrepancy.
v Scalability does not account for the discrepancy.
Note: Each node in a multi-node configuration uses 256 MB of system
memory.
v In a two-node configuration, make sure that both nodes have started and all
the devices between the two nodes have been counted.
v The memory modules are seated correctly (see "Removing a DIMM" on
page 137 and "Replacing a DIMM" on page 138).
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 error message 289. If a DIMM was disabled, run
the Setup utility and enable the DIMM. See Chapter 6, "Configuration
information and instructions," on page 201.
3. Run memory diagnostics (see "IBM Dynamic System Analysis" on page 71).
4. Make sure that there is no memory mismatch when the server is at the
minimum memory configuration (two 1 GB DIMMs).
5. Reinstall the removed DIMMs, one pair at a time, in the memory cards and the
memory expansion module, making sure that the DIMMs in each pair match.
6. Reinstall the removed memory cards one memory card at a time (see
"Removing a memory card" on page 136 and "Replacing a memory card" on
page 137), making sure that the DIMMs on each card match.
7. Reseat the following components:
a. DIMM
b. Memory card
8. Replace the components listed in step "Memory problems" on page 47 one at a
time, in the order shown, restarting the server each time.
9. If the DIMM was disabled, run the Setup utility and enable the DIMM. See
Chapter 6, "Configuration information and instructions," on page 201.
For additional information about memory, see the IBM eX5 Portfolio Overview IBM
System x3850 X5, x3950 X5, and BladeCenter HX5 at http://
www.redbooks.ibm.com/abstracts/tips0054.html.