Asus Maximus XII (Z470) boots straight to BIOS

[Krakadoom]

The last two days, every time I turn on my PC, it displays the post screen, then goes directly to BIOS without any input. If I quit BIOS without saving changes, it boots correctly to Windows after that. If I select the correct line for windows boot manager in the manual boot selection section, it also loads windows correctly. 

I can't work out why this suddenly happens, there is no error message of any kind. I've also tried saving changes when exiting BIOS, but it makes no difference. 

Until yesterday, it had worked fine for years.

[Krakadoom]

Fastboot on or off doesn't matter. Selected boot drive doesn't matter. Using newest BIOS (3201) and Intel ME. I'm stumped. Anyone have ideas?

[MoKiChU]

Hi,

Your CMOS battery is probably dead. Replace your CMOS battery (CR2032) : https://www.asus.com/support/faq/1005740

[Krakadoom]

I was afraid someone would suggest that. Changed it out now, but the issue remains the same.

[MrAgapiGC]

duplicate and take a photo. the test is simple

1. turn off the psu, disconect the psu black cable that goes to the outlet turn on the psu and try to turn on the pc. 5 times is sufficient. 

2. wait 20m (this is the actual coldboot) 

3. once pass that turn on the pc with the card on pcie 16_1.  PLAY with the monitor menu until post. On the hero there is diagnostic lights  RED-CPU \ yellow-ram\white-gpu\green-hd post   photo on all. PLAY WITH MONITOR MENU.  IF THIS FAILS can be GPU or board.  If is gpu check power plug have signal of burns.

4. THE OTHER is to check IF POST and have signal, check what appears. photo there. if the time and date is reset then replace the cmos battery.   If the time and date boot up fine on easy mode check if the boot manager appears. IF APPEAR all is ok. if not the nvme is gone OR is on UEFI or legacy. that can be check as we go!

REMEMBER:  PLAY WITH MONITOR MENU since monitor will go to sleep since take a long time to post!

good luck

[Krakadoom]

#1 and 2 I already do by default every morning, so that's not likely to change anything. 

Can I ask what all these other steps are supposed to be indicating? All due respect, it reads to me like just trying a lot of semi-random things and seeing if something sticks?

There is no indication that this would be a GPU issue. I have already replaced the CMOS battery as I stated, though the clock was never off in the first place. As I also already stated, the boot manager is fine, the correct entries are there, and I can manually boot from bios or I can exit without saving changes, which makes the board follow the set boot order (which works). The only hitch is that it enters bios for no apparent reason, and exiting it just resumes the boot process as normal.

As for the diagnosis LEDs on the motherboard, good point, I'll have to take a look and see if they yield anything. 

[Krakadoom · Accepted solution]

Alright, so after a LOT of tinkering to be able to even install Windows 11, I finally got rid of enough old Asus and Logitech drivers for the install to succeed. The issue, however, remained.

Then, after removing Armoury Crate and ASUS AI Suite 3, and installing "Update for Windows Security platform - KB5007651 (Version 10.0.27840.1000)" from Windows Update, the issue seems to have gone away, at least for now.

Which part exactly worked I'm not sure, but the system just boots to Windows now at least instead of halting in BIOS every time. 

[MrAgapiGC]

is not what it stick, i how test are done. 

aside the 2 nvmes there is another mechanical hd?

[Krakadoom]

There are 3 nvme drives, no mechanical drives.

But since the solution was already pretty much found, there is no point testing any more. My point was that testing hardware randomly isn't a good use of time, unless there is at least some theory as to what might be wrong.

[MrAgapiGC]

outstanding! super week and thanks!