Lenovo 7Y54, Maintenance Manual

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10. Replace the each power supply and check the power button function after installing the each one.
11. If the issue cannot be resolved by above actions, please call service to review the issue symptom and
see whether the system board replacement is necessary.
Memory problems
Use this information to resolve issues related to memory.
• “Multiple memory modules in a channel identified as failing” on page 103
• “Displayed system memory less than installed physical memory” on page 103
• “Invalid memory population detected” on page 104
Multiple memory modules in a channel identified as failing
Note:
Each time you install or remove a memory module, you must disconnect the server from the power
source; then, wait 10 seconds before restarting the server.
Complete the following procedure to solve the problem.
1. Reseat the memory modules; then, restart the server.
2. Remove the highest-numbered memory module of those that are identified and replace it with an
identical known good memory module; then, restart the server. Repeat as necessary. If the failures
continue after all identified memory modules are replaced, go to step 4.
3. Return the removed memory modules, one at a time, to their original connectors, restarting the server
after each memory module, until a memory module fails. Replace each failing memory module with an
identical known good memory module, restarting the server after each memory module replacement.
Repeat step 3 until you have tested all removed memory modules.
4. Replace the highest-numbered memory module of those identified; then, restart the server. Repeat as
necessary.
5. Reverse the memory modules between the channels (of the same processor), and then restart the
server. If the problem is related to a memory module, replace the failing memory module.
6. (Trained technician only) Install the failing memory module into a memory module connector for
processor 2 (if installed) to verify that the problem is not the processor or the memory module connector.
7. (Trained technician only) Replace the system board.
Displayed system memory less than installed physical memory
Complete the following steps until the problem is resolved:
Note:
Each time you install or remove a DIMM, you must disconnect the server from the power source; then,
wait 10 seconds before restarting the server.
1. Make sure that:
• No error LEDs are lit on the operator information panel.
• No memory module error LEDs are lit on the system board.
• Memory mirrored channel does not account for the discrepancy.
• The memory modules are seated correctly.
• You have installed the correct type of memory module (see
“Specifications” on page 1 for
requirements).
• After changing or replacing a memory module, memory configuration is updated accordingly in the
Setup Utility.
Chapter 4
.
Problem determination
103