[SOLVED] Pink square with vertical lines before POST

[mayorsly]

Hello all together,
I have searched for many hours on this and other forums but have not found anyone with this problem, so I am creating a thread myself.

My PC specs:
Ryzen 3500X
ASUS TUF Gaming B550-Plus [WI-FI]
2 x 8 GB G.Skill RipJaws V DDR4-3200
XFX RX 580 4GB
Corsair RM650i
Windows 10 on NVMe Samsung SSD 970 Evo Plus 500 GB

First, let me say that this is just a cosmetic bug that has been driving me crazy for a while.
I assembled the PC about a year ago and everything worked fine.
I did a BIOS update 3 months ago. I think the error has been occurring since then.
When I turn on the PC the first thing that comes up is the following screen. This is before the POST I think.

https://freeimage.host/i/7iZNKx

After that comes the following picture, completely in red.

https://freeimage.host/i/7iZ8AP

Then comes the following Windows loading screen, which is normally black with a blue icon at the bottom.

https://freeimage.host/i/7iZSN1

After that everything is normal. The Windows login screen. All games. Everyday work. Suspend and waking up again. Even booting into UEFI / BIOS works without problems.

Yesterday I tested all previous BIOS versions and completely wiped the CMOS several times (via the UEFI and via the CMOS pins). I also removed the graphics card, reinstalled it, tested Displayport and HDMI on 2 different monitors. Today I tested a Linux live stick, thinking maybe it's a defective driver dropped somewhere by Windows. But in all tests the same error pattern occurred.

I don't have another graphics card to install. The next step for me would be to get one and test it. But maybe someone has another idea.

 

[kerberos_20]

this is normal for rx580, vbios isn't fully UEFI compatible, some vendors did offer vbios update, but most of them ignored it
enable CSM compatibility mode and just set storage to UEFI, that should solve it...but you have to go to bios first...hmm

 

[mayorsly]

this is normal for rx580, vbios isn't fully UEFI compatible, some vendors did offer vbios update, but most of them ignored it
enable CSM compatibility mode and just set storage to UEFI, that should solve it...but you have to go to bios first...hmm

Are you serious? That's what solved it. Thank you very much. I wasted so many hours on this one setting.

As I wrote in the first post, I get into the BIOS normally. Therefore changing the CSM was not a problem.

 

[kerberos_20]

ok, i thought you won't event get bios image, no problem then