Laptop stuck on black screen after switching to Ultimate mode (MUX/dGPU issue)

[DSuspect]

Hello everyone,

Sorry to bother you, but I came across a previous comment from someone experiencing the same issue I’m currently facing — a black screen on boot caused by the MUX switch not initializing the dGPU properly.

My laptop is an ASUS ROG G18 4080 i9 13980HX

Here’s what happened in my case:

I changed the GPU mode in GHelper to Ultimate mode in order to force the dedicated GPU (dGPU) to run all the time, since it wasn’t being used and only the Intel iGPU was active. Unfortunately, that turned out to be a mistake. After rebooting, my laptop now starts up with a completely black screen — I can hear the Windows login sound and even shut it down blindly from the login screen, but there’s no display output at all.

I’ve tried several things, but I can’t even access the BIOS or display anything on the screen. Right now, I’m attempting to fully drain the battery and discharge the components by disconnecting the internal battery from the motherboard and leaving it overnight, hoping it might reset something.

Has anyone managed to fix this issue? Any advice or steps that worked for you would be greatly appreciated.

Thank you so much for your time and help — I’m really desperate to get my laptop working again.

[Falcon2_ROG]

@DSuspect 
Based on your description, we recommend trying to connect an external monitor via HDMI or USB-C (DisplayPort mode) to check if the display output works. If you can see the Windows screen through the external monitor, try entering Safe Mode and uninstalling GHelper or restoring the default GPU mode.

[DSuspect]

Hi,

Connecting to via USB C or HDMI did not work as the GPU is failing to boot up after the computer ran out of battery while on sleep mode ( that’s my theory). However, I managed to deactivate Ultimate mode on GHelper blindly by using the Windows Narrator accessibility feature to guide me on the desktop.

I have a working display now via the iGPU, but still no dGPU. It appeared in Device Manager with an exclamation mark so I proceeded to uninstall it and remove drivers with DDU, but now it is not showing under Device Manager and can’t install any NVIDIA drivers as there’s no GPU detected on my computer. What do you suggest? Should create another post for this?

[Silent_Scone]

Hi @DSuspect 

Have you attempted to do a System Restore prior to removing the GPU with DDU? Usually, the software sets a restore point.

[DSuspect]

Hello,

No I have not. Right now I’m letting my Laptop with its battery disconnected for at least 20 hours for it’s components to fully discharge and maybe with that be able to revive the dGPU. If it doesn’t I’ll proceed with your suggestion and with reinstalling the latest BIOS firmware.

Do you think this should work?