Can't See BIOS/POST/Boot Menu When Primary Screen is Plugged In

[Zarathustra[H]]

Alrighty.

So, I was forced to replace my motherboard (long story) and now that the new motherboard is installed I am having a weird problem.

I have three monitors. Two little dells on the side, and one large Asus ROG 4k screen in the center.

Before I replaced the motherboard, I always got to see POST/BIOS/Grub Boot Manager on my left screen. Since I rotate my screens to portrait mode, it was a little annoying to have to tilt my head, but at least it worked.

Now, with the new motherboard (and everything else, including the GPU, the same) the machine boots fine, but I never get to see the POST, BIOS or Boot Manager screens IF my main screen is plugged in.

If I unplug the main screen, and have only my side monitors plugged in, I see post BIOS and boot manager just fine.

This means that the only way I can change BIOS settings or see POST is to unplug my main screen, and the only way I can boot into Windows is to unplug the main screen, wait for the boot manager to pop up, select windows, and then quickly plug the main screen back in again while it is booting.

This is a royal pain in the butt.

Anyone know what might be going on, or how to solve it?

Much obliged,
-Z

 

[motqalden]

While i do not know the answer to your issue you can arrow down twice and enter (or wait) to select windows once you get the hang of how long it takes for the boot menu to come up

 

[Zarathustra[H]]

While i do not know the answer to your issue you can arrow down twice and enter (or wait) to select windows once you get the hang of how long it takes for the boot menu to come up

Hah, True.

I'm hoping that doesn't wind up being the long term solution though.

I've tried juggling the different monitors from port to port, Main screen always being on DP, but the side screens either both on DP to DVI adapters, or one on native DVI and the other on hdmi to DVI, etc, to no effect.

As long as the main screen is plugged in, I never see the BIOS

 

[Zepher]

What if only your main screen is plugged in, do you see post or bios?

 

[BinarySynapse]

Your main display may just be taking too long to sync up. Look for a setting in the BIOS for “setup delay” or fast boot and see if tinkering with them helps

 

[Zarathustra[H]]

What if only your main screen is plugged in, do you see post or bios?

I think I tried that, and it didn't work, but I can't remember. I will try again.

Your main display may just be taking too long to sync up. Look for a setting in the BIOS for “setup delay” or fast boot and see if tinkering with them helps

Could be. I will look around, thanks.

 

[Zarathustra[H]]

For now, a simpler workaround is to power the main screen off during POST (before it was in standby)

This way I at least don't have to unplug it from the GPU.

 

[pendragon1]

have you shuffled what ports they are connected to? if the gpu has dp, one of them will be primary and override the others and hdmi. see if you can get the 4k on it, usually the left most port when looking at the back of the card.

 

[Zarathustra[H]]

have you shuffled what ports they are connected to? if the gpu has dp, one of them will be primary and override the others and hdmi. see if you can get the 4k on it, usually the left most port when looking at the back of the card.

Yeah, that's where I had it p-lugged in at first.

I'm guessing the main screen struggles with the display mode that the BIOS/POST uses. Maybe I should use a DP adapter and plug one of the side screens into that primary port, and see if that helps.