Crosshair VIII Dark Hero Bios Help

[icenovaa]

Tried to update to the latest bios Version 5101 from my old Version 3003 it said Successful then asked to restart which I did. After restarting my fans would run max speed & I had black screen but I waited 30 minutes to see if it'll resolve on it's own and get to the Windows menu but it never made it there nor did I see the ROG screen. I followed all the instructions perfectly MBR FAT 32 format, used the tool BIOSRENAMER to rename it to C8DH.CAP so why did this happen? I've unplugged my PC, hit the Reset CMOS at the back for 10-20 seconds, plugged in my PC and tried to reflash my old bios(Version 3003) and it still won't work no display.   

Specs 

Ryzen 7 5900X CPU

Asus ROG Dark Hero Mobo

32gb (4x8) Corsair Vengeance RAM

EVGA RTX 3070 GPU

Corasir RM850 PSU 

[criznittle]

Have you tried using the BIOS Flashback dedicated USB port on the motherboard? 

1. Prepare the USB Stick:
Format to MBR FAT32.
Place only the renamed BIOS file C8DH.CAP in the root directory.
2. Locate the Flashback Port:
Use the bottom-most USB port on the rear I/O labeled for BIOS Flashback (usually near the BIOS button).
Plug in the USB stick there.
3. Power Off the System:
Turn off PSU and unplug power cable.
No need for CPU, RAM, or GPU installed.
4. Initiate BIOS Flashback:
Plug in power cable and turn on PSU (don’t power on the system).
Press and hold the BIOS Flashback button for 3 seconds until it starts blinking.
The LED will blink slowly—this means flashing is in progress.
Wait until the LED stops blinking (can take 5–10 minutes).
5. After Flashback Completes:
Power off again.
Reinstall CPU, RAM, GPU.
Power on and check for POST/ROG splash screen

Make sure you're using the correct USB port and that the file is properly renamed. Some boards are picky about USB brand and size—try a 8–16GB stick if possible.

This is from Copilot AI, fed with your specs and details. Let me know what else you've tried, and if you get any specific Q-code. This sounds like a frustrating issue.

[icenovaa]

Hello I’ve done all of that and I still get either an error code AA or or 02 no display on both codes. 

[icenovaa · Accepted solution]

Ok I fixed it I forgot my pcie riser was 3.0 not 4.0 sorry guys for the trouble