Question Have to boot with monitors connected to mobo, then I can switch cables to GPU, only then do I get video output

[systemik]

Just finished upgrading my 9700k platform to 13600k / z790 Aorus Elite AX / DDR5.

With the 2 monitors (Samsung G9 / 17" pos for discord) connected to 3080 ti I get no video output whatsoever. Only if I connect either or both to integrated graphics do I see video output at boot. In the case where I plug one monitor to mobo and one to GPU I also get no video output at boot. If I boot with both monitors to mobo all is well and THEN I can swap both cables to the GPU and all is well. Obviously this is no an acceptable long term solution....

I have tried disabling integrated graphics in bios, resulting in no output whatsoever from gpu. Reset CMOS, same issues.

The only solution has been boot on IGPU and once in to windows swap monitors over to the GPU. Once that is done the system is good to go. Ran some games all seems well.

Also my DDR5 6000 ram is running at something like 2200 but until I sort out the video problem I have not enabled xmp.

Previous to this upgrade I have had 0 issues with the EVGA FTW3 3080ti (current driver installed). Tonight I plan to update mobo bios.

Any suggestions would be appreciated.

 

[Colif]

did you clean install windows?

 

[systemik]

Yes, clean install, new Samsung 990 pro SSD. Should mention though that the copy of windows was several years out of date and needed a plethora of updates. Did not realize until afterwards that I should have grabbed a current build from ms.com

 

[geofelt]

Have you installed the current version of both the Intel IGP and nvidia drivers?

 

[systemik]

Have you installed the current version of both the Intel IGP and nvidia drivers?

Nvidia yes, IGP no.

 

[systemik]

Ok, a few more things I've found while troubleshooting.

The motherboard bios defaults to integrated graphics: ON.

When set to integrated graphics: OFF I get no signal out of either the motherboard or GPU, nada. I have found that with bios set to to AUTO, if I plug my old VGA monitor (using VGA to hdmi adapter) into the GPU while leaving my Samsung G9 monitor unplugged, let it boot to windows on the old monitor, and only THEN plug in the G9 monitor all is well. It's a workaround for now but not a viable long term solution.

Are there any clues in any of this that might make sense to any of you? What could cause having no signal on either monitor if booting with the G9 connected but works fine if plugged after loading windows?

Such a strange issue....