So I was previously running a RTX 3080 with a 12900K on my Dark K|ngp|n. With those components installed I flashed BIOS 1 to the latest version (2.03) by using the usual method (restart the PC, mash the 'DEL' key then get into BIOS settings and update the BIOS firmware from there. All good.
 
Since then i've sold my RTX 3080 and 12900K and have installed a RTX 4090 FE with a 13900KF. So if I flip the BIOS switch to use BIOS 2 or 3 and try to use the same BIOS update method as above, I just get the 53,54,7F POST loop bug because BIOS 2 and 3 are running the old default BIOS version that came with the motherboard.
 
I've tried booting into Windows using BIOS 1 then flipping the BIOS switch to BIOS 2 and attempted a hotflash to version 2.03 but doing so immediately shuts down my system before the flash can complete.
 
I've also tried the other update option of renaming the BIOS .bin file to EVGAE699.bin, putting it on the root of a USB stick, shutting down the PC then using the BIOS flashback button on the I/O. This only results in an E8 error code. I tried a few other USB sticks but the either come up with error E1 or E2. I even tried renaming the .bin file to EVGAE690.bin but the same thing happens. I either get error E1 or E2 or E8.
 
Since BIOS 1 is still working fine, would it be possible for me to restart my PC, mash the DEL key and get into the BIOS settings then flip the BIOS switch to BIOS 2 while i'm in the BIOS settings page and flash BIOS 2 from there? Or would that just destroy BIOS 1?

the_Scarlet_one
Once you are in the gui for the bios, the bios has loaded and you should be able to switch to bios 2 on the board, and try to flash it.

Unfortunately that did not work. 
 
I got into the BIOS gui while using BIOS 1, flipped the switch down to BIOS 2 and tried to install version 2.03 onto it but for some reason the .bin file on the USB was gone. So I flipped the switch back to BIOS 1 and suddenly it saw the .bin file again. Tried the same thing and flipped the switch to BIOS 3 and once again, the .bin file seemed to be missing. Flipped it back to BIOS 1, the .bin file reappeared. 
 
Guess i'm not even allowed to attempt to hotflash BIOS 2 or 3 whilst inside the BIOS gui 
 
So far when I've tried using the other method (BIOS flashback button on the I/O) all that happens is I get error message E1, E2 or E8. Do I need to take my 13900KF out of the motherboard before it will allow me to perform a BIOS flashback?

8Shellac8
-Make sure bios is named EVGAE699.bin
-Load default settings in bios/restart
-Power down system
-Hold the power button down temporarily to discharge the board
-Select bios to flash
-Press and hold the bios button on the rear I/O
-Hold until counter on the debug led finishes
-Should take a few minutes to complete

Yeah I tried that, it doesn't work. I think BIOS 2 and 3 are somehow unflashable/damaged/wiped. I know i'm doing the flashback button method correctly because it works when BIOS switch is on BIOS1. BIOS 2 and 3 are a no go. Error code E8 every time. I've tried 2.02, 2.03, 2.03 beta. I even tried to flash 1.15 just to be sure but no luck.
 
My first successful flash to 2.03 beta (on BIOS1) was back when I had my 12900K and RTX 3080 installed on the board. I'm kicking myself for not flashing BIOS 2 and 3 when I had those components in. I've since sold them so I can't put them back in to try a flash with them installed. BIOS 2 and 3 have been bricked ever since I put the 13900KF and 4090 FE in my system.

8Shellac8
Do you have s3 suspend enabled? If so, try flashing with it disabled. Try flashing with one or no memory installed? Adjust your power setting? Try anything and everything to stop the pc from sleep mode. Sounds like your pc falls asleep installing the bios and refuses to wake up.

Tried all you suggested there but still no luck. 
 
One thing I do notice though is if I go into the BIOS settings menu using my good BIOS1, if I have my USB stick in the USB 2.0 socket (the one next to the RAM) I see the .bin file no problem. Then if i flip the switch to BIOS2 then go back into EXTRAS, when I press flash BIOS the .bin file vanishes. So I flip the switch to BIOS1 again and the .bin file reappears in EXTRAS. Same thing happens for BIOS3 - the .bin file vanishes then reappears when I flip the switch back to BIOS1 again. 
 
If BIOS chips have data partitions on them then i'm pretty sure those partitions on BIOS2 and 3 are dead and gone. 
 
I have also attempted to hotflash by using BIOS1 to get into Windows then flip the switch to BIOS2 or 3 and hit the update.bat file. When I press 'Y' to flash, my PC immediately shuts itself off. I think this may have been what murdered BIOS2 and 3.
 
Interestingly though, if go into the BIOS settings menu using BIOS1 then Disable Intel ME, boot back into windows, flip the BIOS switch to BIOS2 or 3, with Intel ME disabled I can then begin a hotflash and my PC stays on for the whole flash process. Unfortunately though, when it gets to the end of the hotflash I am presented with this error message below, telling me the flash failed. This was using the update.bat file from BIOS 2.03 Beta 2 (the one EVGALeeM posted that includes the 4090 FE no display fix). It seems that the only part of the flash that is failing is the verification right at the end.
 

Have you tried to flash with just the bare board? Seems we're getting closer and maybe it's a hardware compatibility issue.

-Unplug psu, turn power switch on to discharge
-Discharge board
-Pull the CMOS battery and let the board sit, the longer the better but usually 5 min will do.
Put battery back in and just see what booting up does on all 3 switches.

Make sure if you have any bios profiles you need to save on a flash drive. This may clear cmos all bios switches.

E2 and E8 are both related error codes to the suspend function supposedly. Nothing I could find for fixes relate to any of the settings available to us. Except the suspend function. They go into older stuff like ACPI, so may be related to storage drives.

Maybe your chipset drivers got corrupted, Reinstall may be in order. Reinstall the ME driver as well.

Also, check your cpu mount. My IHS was completely borked causing an uneven mount causing all of my issues. Check my last post in the 13900k oc tips thread.

Doing the hotflash from within Windows is what murdered BIOS 2 and 3 for me. The second I pressed Y to begin the hotflash, the entire PC shut itself down. Now those BIOS are unrecoverable no matter which method I use. BIOS 1 works fine because a flashed that to 2.03 back when I had my old 12900k installed. And notably I flashed that BIOS from within the BIOS menu (before booting into windows).

I’m just kicking myself for not flashing BIOS 2 and 3 the same way, before selling the 12900k. If I’d flashed all 3 BIOS from the BIOS menu, BIOS 2 and 3 would still be alive. But lesson learned - NEVER hotflash BIOS from within Windows.

Sajin
The hot flash didn’t cause your issue. The shutdown while attempting to flash was the problem. EVGA specifically says to hot flash to recover corrupted bios… https://www.evga.com/supp...tails.aspx?faqid=59733

Well since I no longer had the 12900k, BIOS 2 and 3 would not let me access the BIOS menu with the 13900KF in my system. The only options left were to boot into Windows using BIOS 1 (which had been flashed to 2.03 already), flip the BIOS switch to BIOS 2 or 3 and try to perform a hotflash. Or try using the BIOS flashback button. Unfortunately I tried doing the hotflash from within Windows first. Pressing the 'Y' button to begin the hotflash immediately shutdown the PC and killed BIOS 2 because like you say, the immediate shutdown cut the power during the flash.

I figured I could try again after updating to the Intel Management Engine and Chipset drivers. Booted into Windows with BIOS 1, flipped the BIOS switch to BIOS 3 and tried to hotflash it to 2.03. Again, soon as I hit 'Y' to hotflash, the PC immediately shutdown and the flash failed. So hotflashing in Windows killed my 2 spare BIOS. And now I can't get them back, not even with the BIOS flashback button. Hotflashing within Windows is lethal. I wouldn't recommend anyone attempt it. Stick to BIOS flashing from the BIOS GUI menu (the old school way). And if you can't do that, use the BIOS flashback button instead.

Sajin
Strange that it shutdown immediately when pressing Y. Seems like an issue in the script that evga has written.

It does indeed. It shuts down when I press Y to begin the hotflash if Intel ME is enabled in the BIOS. If I disable Intel ME first then boot into windows and attempt the hotflash to BIOS 2 or 3, after pressing Y the flash goes through the full process without any instant shutdowns. Only trouble is, once the hotflash reaches the end, it says 'Error 207 - Data verify mismatch found. FTP operation failed.' Then it just asks me to restart my system and i see BIOS 2 (or 3 if i have it switched to that) hasn't updated at all. Only BIOS 1 will post. BIOS 2 and 3 remain completely blank and corrupted/unflashable.

Sajin
Wow. Guess you’ll need to send your board in for them to correct the bios chips for you.

Think I’ll just cut my losses and get a Z790 K|ngp|n when that board finally releases.