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BIOS Flashback & EZ Flash both failing...

S4lticid
Level 9
Hi there, could really use some help here...

Just finishing up my build. I suppose I should have updated BIOS first, but that's water under the bridge now - I'm very cautious about doing that, makes me super nervous and would rather not unless I have to so I think about it too much before doing it.

My Mobo is ROG Maximus XI Hero.

Anyway, I finished updating the drivers and Windows, and even downloaded my main game. Then finally decided I should update BIOS before installing benchmarking or Aura Sync etc. But of course, I who am so cautious about flashing BIOS, am finding I now seem to not be able to at all.


  • I am unzipping the download.
  • I've tried re-downloading
  • I've used the re-naming script that comes with the download to make sure it's renamed.
  • File is at root on the USB with nothing else on it.
  • First used a 16 GB USB 2.0 fresh formatted to FAT 32
  • Tried first with BIOS Flashback port - light just stays on indefinitely
  • Tried adding WIFI to the name because I read that was an issue with the Hero X BIOS but it didn't make a difference
  • Tried a 4 GB USB 2.0 fresh formatted to FAT 16 after the first failed.
  • Tried renaming tool and then with added WIFI to the name as well
  • BIOS Flashback does the same thing - the light on the USB comes on, so it's read, but then nothing and the Flashback light stays lit indefinitely


Once all this failed, I tried EZ Flash from within BIOS.
I tried this from both the Flashback USB Port and another port. Each time I tried:

  • At first EZ Flash has External Storage option disabled like it can't find any drives. So, I hit escape to back out.
  • Then suddenly I'm on a screen where it can detect the file on USB.
  • I select the new BIOS file...
  • EZ Flash and BIOS in general freezes and does nothing. I am locked out of keyboard.
  • Only thing I can see at this time is a Q-Code of b-4, which as I understand is USB Hotkey, but I don't know what that means in this context.


Every try with either utility, I have had to do a hard reboot. Each time the machine boots up fine, no issues. Just BIOS will not update.

Does anyone have any ideas?
I am at a loss and have tried everything I can find online. I guess my next step is to reset CMOS but I'd rather not unless I have to.
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6 REPLIES 6

Silent_Scone
Super Moderator
The EZ Flash Process needs to process the ROM before continuing. Are you sure the progress bar wasn't processing? Seems odd you're struggling with both flash methods.

Make sure XMP is not applied along with any other overclocking, the UEFI should be at complete defaults prior to updating.
13900KS / 8000 CAS36 / ROG APEX Z790 / ROG TUF RTX 4090

Thank you so much for your reply Silent Scone.
I agree, it is definitely odd.

To answer your question, there is no progress bar at all to EZ Flash. I literally select the file and nothing at all happens, except that the screen and keyboard become unresponsive and I cannot do anything. Everything freezes on that select screen and I believe that's when the b4 q-code appears on the lcd (though I need to double check that). EZ Flash never proceeds to any next step. I left it there for a half hour hoping something might happen and nothing. At that point I figured it was just another failure.

I haven't changed any settings from stock BIOS at this time except to disable the CPU Fan and secondary CPU Fan monitors because I'm liquid cooling. And of course the boot order to the Windows disk. Unless the mobo comes with XMP enabled as stock, then it shouldn't be on. Perhaps you know if that's the case or not? But I will double check tonight regardless.

Do you think the q-code is giving any indication of what might be going on here? Or is that simply expected considering the failure to read the file from the USB - because that does appear to be where the failure is happening.

Arne_Saknussemm
Level 40

Thank you Arne, I shall give this a try tonight.

So a CMOS clear is definitely in order then. Hoping this works.
If it doesn't though, I'm more likely to just live without updating BIOS rather than having to tear down my build after spending so much time putting it together.

I am still wondering why it appears to be failing at the USB read. The q-code bothers me. Is it possible something went wrong with the driver updates? There were a couple of intel ones that didn't want to install, mostly surrounding graphics if I recall. I assumed it was because I'm using a discrete card. But it's possible one might have been SATA rapid storage or something related as well...

Edit to add: Ugh, just did some quick reading on bios chips and symptoms of them potentially going bad. Damn. Really hope that's not the issue. I'm not seeing any of the classic symptoms at all so I'm hoping.
How I wish I didn't have to work today. LOL

Arne Saknussemm wrote:
Try this on the pendrive and then download a fresh BIOS file...and rename it for BIOS Flashback...
https://rog.asus.com/forum/showthread.php?78620-X79-DELUXE-Bricked-after-USB-BIOS-Flashback&p=549397...

My sincere apologies for the double post, but I had to extend my deepest and happiest gratitude! Thank you so much!
BIOS updated! All is well and running smoothly!

Thank you again!

Arne_Saknussemm
Level 40