ProArt z790 bio flashback led is always blinking

[rbmanian75]

I’m experiencing an unusual issue with my ASUS ProArt Z790 motherboard. The system was working fine until recently, but now it fails to power on normally.

Symptoms

• The BIOS FlashBack LED blinks continuously, even when no USB drive is connected in bios usb port

• The system will only power on if I:

1 Turn off the PSU.

2 Turn the PSU back on and immediately press the power button.
Once powered on, everything works perfectly (BIOS, OS, stability all normal).

• However, after shutting down, the system will not start again — the FlashBack LED just keeps blinking.

Troubleshooting Performed

• Updated BIOS to the latest version using the EZ Flash utility (not FlashBack).

• Cleared CMOS and loaded optimized defaults.

• Enabled ErP S4+S5 in BIOS.

• Verified PSU and all component connections.

• Tried full power drain (unplugged PSU, pressed power button, removed CMOS battery for 10+ minutes).

• Observed that the FlashBack LED continues blinking as soon as PSU power is applied.

Additional Observations

• The FlashBack button on the I/O panel physically clicks when pressed.

• I’ve read reports suggesting that on some units, the I/O shield may press against the FlashBack button, causing it to remain partially engaged. The LED behavior seems consistent with that possibility.

• I plan to check motherboard and backplate alignment to ensure the button isn’t being pressed mechanically.

Question

Could this issue be caused by the FlashBack button or controller being stuck in an active state?
If so, is there a recommended method to reset or disable the FlashBack controller, or would the motherboard require service/RMA?

Any insights or official troubleshooting steps from ASUS would be greatly appreciated.

[JohnAb]

I was thinking that the flashback button could be stuck, but in that case I think it's likely that it wouldn't click. Perhaps the switch is broken internally, but I think that's not likely. 

Could you try fiddling with the switch and seeing if you can get a boot without the flashing LED? If so, leave it since you won't need it, just use Flash Back 3 in the BIOS instead (or RMA the board if nothing helps). 

I don't know what else to suggest. 

[rbmanian75]

Thanks for the reply. i tried fiddling with the flashback button/switch dnd it did not help either. always i need to use psu button and power button simultaneosuly to switch on. i have contacted asus support the pointe me to this link https://www.asus.com/support/faq/1042632/ in that link they did not mention anything about bios flashback led. i have contacted again with the details. let me see what they say.

[JohnAb]

No problem and good luck. Seems like an odd issue. 

[rbmanian75]

Asus asked me to RMA via reseller. I am sedning it for RMA. it may take a month to get a resolution for the RMA. 

[Ncroglio]

I have this same issue.  Please let me know when they fix it and how it goes.

[rbmanian75]

The retailer send it to asus and in end the they are refunding me. I upgraded to ProArt z890 and Core Ultra 9 285K.