UHD panel upgrade T14/T15 gen 2: odd behaviour

[iamdmc]

Hi all. I'm trying to do some problem solving... I bought my father a 15.6" UHD panel upgrade (AUO B156ZAN04.1) to replace the original FHD panel in his T15 gen 2. I bought a compatible 40-pin eDP UHD cable (narrow 0.4mm pitch) and connected the panel and board

photos: https://imgur.com/a/Ln1YZGY

On boot, the Lenovo logo displays correctly, and BIOS also displays correctly. When booting into ubuntu, the picture displays correctly at 3840x2160

However... in Windows 10, there are vertical stripes across the whole screen and it appears black and white. It seems almost as if the RGB channels are out of horizontal synch, as they seem offset from each other. It seems like an hsynch issue - which I've never come across on a digital video signal, but was not uncommon with analog VGA

Laptop is on the Newest Windows 10 update, newest BIOS, newest Intel graphics driver, newest ThinkPad Monitor file, and newest NVidia T500 graphics driver...

I've tried disabling the Xe graphics driver - without change. Same with disabling the NVidia driver.

any ideas? It seems almost certain to be a driver issue... I just can't figure out which one

I've also tried a 40 pin eDP 0.5mm pitch cable with a QHD 2560x1440 panel, and UHD 3840x2160 panel and it works perfectly...

[iamdmc]

Update: after I first tried this on my P14s gen 2 (identical to T14 gen 2) motherboard, I tried it on my T15 gen 2 motherboard. On the T14 gen 2 it always looks like the striped image. It works on the T15 gen 2 motherboard, but if I go on 'standby' then reopen the laptop it again looks like the striped image. Since the P14s, T14, and T15 gen 2 share an identical motherboard - I'm totally puzzled by this

Strangely, if I hibernate or shut down (whether full shut down or Windows 10 modern shut down) the image comes back normal. For now I've disabled standby in every possible way.

So it's definitely a driver issue. And no, resetting the driver with Win+Ctrl+Shift+B does nothing. I've tried several times to uninstall and reinstall the Intel display drivers, but still no change.

I still get an error "2203: system configuration is invalid" every time the system starts up from cold boot, modern shut down, or waking up from hibernation. I have no idea how to fix this...

[mikemex]

I still get an error "2203: system configuration is invalid" every time the system starts up from cold boot, modern shut down, or waking up from hibernation. I have no idea how to fix this...

Maybe the panel EDID's (or equivalent) is damaged. Or maybe there is a display panel whitelist in the BIOS...

[iamdmc]

I still get an error "2203: system configuration is invalid" every time the system starts up from cold boot, modern shut down, or waking up from hibernation. I have no idea how to fix this...

Maybe the panel EDID's (or equivalent) is damaged. Or maybe there is a display panel whitelist in the BIOS...

I suspect a soft whitelist