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35116
May 23rd, 2015 04:00
R815 no POST after switching UEFI-BIOS boot mode
While attempting to troubleshoot an upgrade of AMD CPU's in an R815 server running Windows 2012 Server, I set the boot mode from UEFI to BIOS mode. (In retrospect, it looks like this is a neophyte mistake!) The machine will no longer POST, and immediately shuts down. I found the following in one of the Dell manuals:
"Troubleshooting System Startup Failure
If your system halts during startup prior to video output or LCD messaging, especially after installing an operating system or reconfiguring your system's hardware, check for the following conditions:
• If you boot the system to the BIOS boot mode after installing an operating system from the UEFI Boot Manager, the system will hang. The reverse is also true. You must boot to the same boot mode in which you installed the operating system. See Using the System Setup Program and UEFI Boot Manager."
and...
"Choosing the System Boot Mode
The System Setup program also enables you to specify the boot mode for installing your operating system:
• BIOS boot mode (the default) is the standard BIOS-level boot interface.
• UEFI boot mode is an enhanced 64-bit boot interface based on Unified Extensible Firmware Interface (UEFI) specifications that overlays the system BIOS. See Entering the UEFI Boot Manager for more information on this interface.
You must select the boot mode in the Boot Mode field of the "Boot Settings Screen" of the System Setup program. After specifying the boot mode, proceed to install your operating system in that mode. Thereafter, boot the system to the same boot mode (BIOS or UEFI) to access the installed operating system. Trying to boot the operating system from another boot mode causes the system to halt immediately at startup."
However - I haven't found any information about rescuing the situation, so that I can get back to any kind of booting process. (Have tried resetting NVRAM, and booting from USB with DOS-formatted stick with BIOS replacement - without success).
Any pointers would be gratefully accepted!
Daniel My
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6.2K Posts
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May 23rd, 2015 11:00
Hello
What issue were you encountering with the upgrade? Have you installed the old CPUs back into the system to see if the system will function with them?
What exactly is the system doing? Are you getting a splash screen? Are you able to enter the system BIOS? Are you getting any LCD errors? Is there any video output?
How did you reset NVRAM? Did you drain flea power? Did you use the jumper? Most people remove the CMOS battery to clear NVRAM. The CMOS battery only maintains the system clock on our servers and removing it will not clear NVRAM.
Thanks
jh295
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May 23rd, 2015 19:00
Hi - thanks for the message.
I was upgrading 4x 12 core Opteron 6100's to 16 core Opteron 6300's in a Dell R815. The machine booted up with the new CPUs, but showed a slightly lower benchmark score than with the old CPUs....and I was attempting to ensure that the latest firmware and drivers were on board.
During this, I think that I set the startup mode to BIOS, from UEFI. (I'm not experienced with these servers, and didn't realise the consequences). The machine was running 64-bit Windows Server 2012 with UEFI. The machine then wouldn't POST on restart. The fans spin up, machine beeps, and closes itself down within a few seconds. No video, no splash screen, no LCD errors.
I replaced the old CPUs. I reset the NVRAM using the jumper (and pulled the battery). I've pulled the disks and RAM. Have also tried restarting with a SBUU disk - no joy with any of this.
I'm wondering if the problem stems from the switch between UEFI and BIOS, or may be more substantial.
Thanks for any advice with this. Jim.
Daniel My
12 Elder
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6.2K Posts
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May 24th, 2015 10:00
Hello
The last generation I'm aware of that had audible error codes was 8th gen. Are you sure it is beeping. Usually when people are hearing beeps from the server it is actually coming from another faulty device like a UPS. Maybe this is a UPS power issue? Check to see where that beep is coming from.
I wouldn't bother with trying to boot to disks. That is the boot process and this appears to be a no POST issue, so you aren't making it to the boot process. No POST troubleshooting entails taking the system to minimum to POST. It sounds like you have performed most of the no POST troubleshooting. If you have not already then take the system to minimum to POST(1 CPU, 1 DIMM, disconnect backplane, etc). Also, make sure you disconnect external devices when going minimum to POST. People often forget to disconnect USB storage and other items when doing this.
If the issue still persists after minimum to POST, clear NVRAM, and drain flea power have been performed then it is likely the system board will need to be replaced. Swap power supplies and all other components you have extras of to rule out other issues first though.
When you cleared NVRAM it should have set the mode back to the default of BIOS.
Thanks