Question No output to external monitor depending on GPU setting in the BIOS ?

[JQM_]

Laptop model: Sager NP8358F2

Last year my screen broke and since then I've been using it as a "halftop", without the screen. So I took the screen off. It looks like a Commodore now. Kind of neat.

If the BIOS is set to "MSHybrid", the BIOS (and any non-OS menus, like Advanced Startup, GRUB, etc.) does not output to an external screen. Just an OS. Inside the OS, I see that the dedicated GPU, an RTX 2070 Super, is clearly the only one being used, proper behavior for HDMI/USB-C screen out.

If I set the BIOS to "Discrete", the BIOS (and any non-OS menus, like Advanced Startup, GRUB, etc.) DO output to an external screen. However the OS will not. Using TeamViewer, I can see see things, and that the OS doesn't even recognize there's actually a GPU! It only uses Microsoft's basic display driver, because it literally does not see a GPU, at all.

To my knowledge this feature I am describing is called the "MUX switch"?

My BIOS version, reported by the CMD command "wmic bios get smbiosbiosversion":
SMBIOSBIOSVersion
1.07.07LS1

I have tried output via USB-C and HDMI. Same results for both "MSHybrid" (Integrated) and "Discrete" (Dedicated) options. Is there any way to fix this?

 

[JQM_]

Update

So this is pretty interesting... Pardon my linking another forum, but I brought this up on a few different sites.

https://notebooktalk.net/topic/2400...-bios/?do=findComment&comment=50207&_rid=1895

A user there posted a diagram of how this laptop's MUX switch works, and a diagram of how the dGPU handles the settings. He suggested that it seems to be a VBIOS issue of it not waking up for some reason when set to "Discrete" in my BIOS.

So then I decided to try and switch to Discrete (with the help of flashlights, and TeamViewer), and update my drivers...

https://notebooktalk.net/topic/2400...-bios/?do=findComment&comment=50210&_rid=1895

It did work for a bit. Until I restarted. Then it boots back into not being detected/properly, like it isn't woken up.

If it's a VBIOS issue, what can be done here? Anything?