Memory Problems - Lenovo ThinkSystem SR860 Maintenance Manual

3. If you are using a USB hub, disconnect the USB device from the hub and connect it directly to the
server.

Memory problems

Use this information to resolve issues related to memory.
• "Displayed system memory less than installed physical memory" on page 179
• "Multiple DIMMs in a channel identified as failing" on page 179
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 DIMM 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.
• 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.
• There is no memory mismatch when the server is at the minimum memory configuration.
2. Reseat the DIMMs, and then restart the server.
3. Check the POST error 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, reseat the DIMM; then, run the Setup utility and
enable the DIMM.
4. Run memory diagnostics. When you start a server and press F1, the Lenovo XClarity Provisioning
Manager interface is displayed by default. You can perform memory diagnostics from this interface.
From the Diagnostic page, click Run Diagnostic ➙ Memory test.
5. Reverse the DIMMs between the channels (of the same processor), and then restart the server. If the
problem is related to a DIMM, replace the failing DIMM.
6. Re-enable all DIMMs using the Setup utility, and then restart the server.
7. (Trained technician only) Install the failing DIMM into a DIMM connector for processor 2 (if installed) to
verify that the problem is not the processor or the DIMM connector.
8. (Trained technician only) Replace the system board.
Multiple DIMMs in a channel identified as failing
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. Reseat the DIMMs; then, restart the server.
2. Remove the highest-numbered DIMM of those that are identified and replace it with an identical known
good DIMM; then, restart the server. Repeat as necessary. If the failures continue after all identified
DIMMs are replaced, go to step 4.
.
Chapter 4 Problem determination
179