Lenovo ThinkSystem SR850, Maintenance Manual, Page: 157 / 184

• 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.
3. Return the removed DIMMs, one at a time, to their original connectors, restarting the server after each
DIMM, until a DIMM fails. Replace each failing DIMM with an identical known good DIMM, restarting the
server after each DIMM replacement. Repeat step 3 until you have tested all removed DIMMs.
4. Replace the highest-numbered DIMM of those identified; then, restart the server. Repeat as necessary.
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. (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.
7. (Trained technician only) Replace the system board.
Monitor and video problems
Use this information to solve problems related to a monitor or video.
• “Incorrect characters are displayed” on page 149
• “Screen is blank” on page 150
• “Screen goes blank when you start some application programs” on page 150
• “The monitor has screen jitter, or the screen image is wavy, unreadable, rolling, or distorted.” on page 150
• “The wrong characters appear on the screen” on page 151
Incorrect characters are displayed
Complete the following steps:
Chapter 4
.
Problem determination
149