Cannot enable a DIMM in UEFI F1 setup (DIMM not initialized) - IBM System x

Resolving The Problem

Source

RETAIN tip: H195188

Symptom

After installing or replacing a memory DIMM, some of the memory is not recognized by the system. The total installed memory reported during Power On Self Test (POST) or by the Operating System (OS) is less than expected.

Additionally, the Unified Extensible Firmware Interface (UEFI) local Setup (<F1> Setup --> System Settings --> Memory --> System Board DIMM Details) does not show a DIMM as being in the disabled state.

The User Interface (UI) correctly indicates that a DIMM is present and notes in the help text that it is not currently initialized. The UI does not, however, indicate that the DIMM is disabled. Since the UI does not read the DIMM as disabled, there is no way to enable it in F1 Setup.

Affected configurations

The system may be any of the following IBM servers:

• iDataPlex dx360 M2 Server, Type 6380, any model
• iDataPlex dx360 M2 Server, Type 7321, any model
• iDataPlex dx360 M2 Server, Type 7323, any model
• BladeCenter HS22, Type 7870, any model
• System x3550 M2, Type 7946, any model
• System x3650 M2, Type 7947, any model

This tip is not software specific.
This tip is not option specific.

The following system BIOS level(s) are affected:

• UEFI Levels 23A or 23C

The system has the symptom described above.

Solution

The inability to enable DIMMs via F1 Setup was corrected in the following release '24' builds (and higher) UEFI System Firmware:

• P9E124A for BladeCenter HS22
• D6E124A for System x3550 M2, System x3650 M2
• TME124A for iDataPlex dx360 M2

The files are available from the IBM System x downloads support Web site.

The user should update their server firmware and then enable any disabled DIMMs by selecting F1 Setup --> System Settings --> Memory --> System Board DIMM Details.

Note: Once the user enables DIMMs, they need to press Esc to return to the Main setup screen, and select Save Settings; otherwise, the DIMMs will remain disabled.

Workaround

1. Capture the current server configuration so that it can be restored (if needed) using one of these methods:
   1. Use the Advanced Settings Utility (ASU) to save the current settings.
   2. Manually note settings via F1 Setup.
      
      
2. Restore the server configuration to the defaults using one of the methods below:
   1. Use ASU (standard user release version) to load the server settings to defaults (see the README included with the ASU program).
   2. For BladeCenter HS22, pull the blade and remove the CMOS Battery (use Real Time Clock (RTC)-CMOS clear switch as well).
   3. For System x servers, disconnect the AC and remove CMOS Battery (or alternatively, use RTC-CMOS clear switch).
   4. From the UEFI Setup, select Load Default Settings and then Save.
      
      
3. Restore the captured server configuration from step 1 (if needed).
   
   

Additional Information

The root cause of this issue is that the UEFI "F1" Setup Form, responsible for reporting the operational status of Memory DIMMs, is unable to retrieve the Disabled/Enabled state information in the affected builds.

Note: The status information such as "present and enabled," size, and SMBIOS Type 17 information is not affected by this issue.