Please try to clear the cmos on your system:
Power off the system.
Open up the system so you can see the motherboard.
Locate the CMOS jumper by referring to the motherboard manual and how to clear the CMOS. In general, the CMOS jumper is three pins located near the battery.
In general, CMOS jumper has positions 1–2 and 2–3. Move the jumper from the default position 1–2 to position 2–3 to clear CMOS. Wait 20 minutes then move it back to the default position.
Power on the system. In some systems, you might need to enter BIOS to reset to the factory defaults.
Please check the https://www.intel.com/content/dam/support/us/en/documents/motherboards/server/sb/s2600gzgl_tps_r2_4.... technical product specification for more information, page 91.
If the problem try to perform a https://downloadcenter.intel.com/download/27786/Firmware-Update-Package-Update-for-EFI-Intel-Server-... BIOS recovery:
BIOS RECOVERY INSTRUCTIONS:
The Recovery process can be initiated by setting the recovery jumper
(called BIOS Recovery Boot Jumper).
A BIOS recovery can be accomplished from a USB Mass Storage device.
Please note that recovery from USB floppy is not supported on this platform.
The recovery media must contain the following files under the root directory:
2. UEFI iFlash32 11.0 Build 8 or higher (including ipmi.efi )
BIOS starts the recovery process by first loading and booting to the recovery
image file (RML.ROM) on the root directory of the recovery media (USB disk).
This process takes place before any video or console is available. Once the
system boots to this recovery image file, it will boot automatically into EFI
Shell to invoke the Startup.nsh script and start the flash update application
(IFlash32.efi). IFlash32.efi requires the supporting BIOS Capsule image file
(R02.06.0002Rec.CAP). After the update is complete, there will be a message displayed
stating that the "BIOS has been updated successfully" indicating the recovery
process is finished. The user should then power off the system and switch the
recovery jumper back to normal operation before starting the system.
The following steps demonstrate this recovery process:
1. Power OFF the system.
2. Insert recovery media.
3. Switch the recovery jumper. Details regarding the jumper ID and location
can be obtained from the Board EPS for that Platform.
4. Power ON the system.
5. The BIOS POST screen will appear displaying the progress and system
automatically boots to the EFI SHELL.
6. Startup.nsh file executes, and initiates the flash update (IFlash32.efi)
with new capsule file (R02.06.0005Rec.CAP). The regular IFlash message will be
displayed at the end of the process, once the flash update succeeds.
7. Power OFF the system by using the front panel button or the "reset -s"
EFI Shell command, and revert the recovery jumper position to
8. Power ON the system.
9. Do *NOT* interrupt the BIOS POST during the first boot.