Some thoughts...

How long did you wait before powering it off?

Have you tried reseating the eDP cables? I had this issue when I installed my AMD mainboard, but it showed up in the diagnostic lights (11 green, 1 red) so I knew what to look for.

Do you see anything on the display if you shine a bright light on it? If you see stuff when you shine a light then it's most likely a backlight fuse.

You didn't ask but as a huge advocate of Linux Mint I want to share that I installed Linux Mint 21.2 Cinnamon Edge on my AMD Framework laptop and have found that it works 'out-of-the-box', zero issues at all.

Disclaimer: I upgraded the BIOS to 3.03 before installing an OS—don't know how it would have fared on 3.02.

It's probably fine, but when I repasted my 12th gen mainboard with Thermal Grizzly Kryonaut I saw a noticeable improvement, so I figured I'd just repaste the AMD while I was poking around with the internals. So far so good.

I've never had a problem with Kryonaut and found it an improvement vs. the stock paste on my 12th gen mainboard, so I'm sticking with it for now.

I installed the AMD mainboard last night and repasted with Kryonaut before powering it on for the first time. So far so good.