No Bios Post with error code 66 on X299 Gaming Carbon Pro Help!

[charlesstephenstx]

After saving the primary bios settings by clicking the F10 key I do not get a bios post or display, just a black screen! I see error code 66 on my motherboard. I can still access windows on my secondary bios but nothing on the primary. How can I fix the issue with my primary bios so I can access it? I only use the my primary bios not the secondary. I'm forced to now use the secondary bios until this matter is resolved.....

 

[charlesstephenstx]

I also tried clearing the bios and had no luck. Code 66 is when the bios can't find the OS. I'm not sure why I'm getting this error code after saving the bios settings. Everything was working perfectly fine until recent. I can access windows on my secondary bios but not on the primary. Man this sucks!

 

[charlesstephenstx]

No luck so far, I removed 16GB of memory, reseated the video card in second PCI-SLOT. I disconnected additional SATA drives since my main OS is on an M.2 drive. I also cleared the bios with the button on the back of the IO plate. I also cleared the bios with covering up the JAB1 jumper pins with a cap for 5 to 10 seconds. I'm still not having any luck accessing the primary bios. The only way to access my computer is on the secondary bios which boots into Windows 11 just fine.

 

[Alan J T]

YA ok so can you DL the Bios for your board and use Flashback to flash the bios with the problem,

With a bit of luck reflashing the bios should sort it out

Pretty sure doing the flashback is only option you may have since nothing else has worked
F9 is save profile

F10 is save Bios setting

 

[SumGuy]

Are you sure that Code is 66? It looks like it says b6 to me...
Driver Execution Environment (DXE) – main hardware initialization
B6 - Clean-up of NVRAM

 

[SumGuy]

I could be wrong, but it sounds like memory training issues to me. Maybe try disabling Memory Fast Boot by going to:
BIOS > OC > OC Explore Mode [Expert] > Memory Fast Boot [Disabled]

Disabling that's helped a few people with RAM/BIOS stability issues on AMD systems lately, and I've seen some other forums from a couple years ago with Intel systems having luck with it disabled as well. I'd be really interested to see if this starts happening more often on Intel PCs too. It might just become a commonplace hurdle with all the faster/higher clocked RAM and other components these days. You may have longer boot times after disabling it because it enables full memory training, but it shouldn't hurt anything to disable it.

 

[charlesstephenstx]

Thanks MSI team! I will explore and try all the options provided. It's really great to get a technical scenes of connection with you all online. Thank you!