Question Motherboard stuck in Q code 99 after power was unplugged, and now no display after bios update

[alexander65536]

Hi,

I built a gaming computer 2021 and these are my specs,

Asus ROG Maximus Hero Z690

Intel 12900K

2x G.Skill DDR5 16G memory @ 6000MHz

3 x Samsung 980 Pro

Nvidia ROG 3080 ti



Since first day I have had this issue that if I unplug the power the computer cannot POST and gets stuck in q code 99. Usually clearing CMOS etc has done the job to boot it once and then after that it works flawlessly.



Two days ago I accidentally unplugged it and since then its been stuck in q code 99. tried everything from disconnecting components to bare bones and clearing CMOS, but nothing works. I read somewhere that flashing the MOBO to an earlier version might help and when i did the USB BIOS Flash it stopped showing anything on screen and now its just a black screen. This is really frustrating and would love any help that you can provide.

 

[Darkbreeze]

What version was installed before you rolled back, and what version did you roll back TO?

I would try using the BIOS flashback feature to update it back to the latest version, then after a successful flash I'd completely remove the graphics card from the system and connect your display cable to the motherboard output. With the power cable unplugged from the wall, remove the CMOS battery for five minutes. During that five minutes push the power button on the case for 30 seconds continuously. Now reinstall the CMOS battery. Plug the PSU back into the wall and power up using the iGPU for display.

If there is still no output, power back off, reinstall the graphics card and try again. If there is still nothing on screen, then you likely have a bricked board and will need to send it back to ASUS for warranty replacement if it is still under warranty, generally 3 years from the date of purchase for basically all motherboards.

 

[alexander65536]

Damn yes that is what I feared. I have already done all of the steps but I will try doing it one more time and if it doesn't work just contact asus.

 

[Darkbreeze]

I would also at least TRY this before throwing in the towel because there is always a chance the problem is related to another piece of hardware that's part of the equation.

Flip the switch off on the back of the PSU and unplug it from the wall. Remove the CMOS battery.

Remove all the RAM except one stick, and that one should be in the A2 slot.

Remove ALL of your M.2 drives and disconnect any SATA drives that are connected including both power and data cables.

If you have ANY other hardware like RGB or ARGB hubs or controllers connected to the motherboard, disconnect them.

Remove the graphics card, or if it's already removed leave it removed, completely from the motherboard. That does not mean just unplug the video and power cables from it, it needs to totally be removed from the PCIe slot.

Make sure your display cable is connected to the motherboard.

Reinstall the CMOS battery. Plug the PSU back into the wall. Flip the switch on the back of the PSU back on. Power on.

If you still have nothing, TRY a different monitor or tv. You'd be surprised how many times I've seen guys go through all this just to find out it's the monitor or the display cable.