Clevo P775DM3 lcd upgrade problem - high refresh rate not working

[PorcGras]

Hey guys! I need a bit of help 😞

I recently got a B173QTN01.5 screen (2560x1440 at 120Hz) for my P775DM3 (QTJ1 + 3070)... but it seems stuck at 60Hz (60.025 to be exact). I'm pretty sure I got the right cable: 6-43-P7751-221-1N as I followed the combinations on the Eurocom website.
Setting the frequency to 120Hz in either Nvidia Control Panel/CRU makes the screen go crazy (full black + white horizontal lines).

Am I missing something? Am I doing something wrong?
Thankuu!

[harkaz]

The Eurocom website lists 6-43-P7751-221-1N for P775TM1/QHD-120Hz and 6-43-P7751-221-1L for P775DM3/QHD-120Hz.

[PorcGras]

1 minute ago, harkaz said:

The Eurocom website lists 6-43-P7751-221-1N for P775TM1/QHD-120Hz and 6-43-P7751-221-1L for P775DM3/QHD-120Hz.

I think/hope they are interchangeable... 😞 I mean, the monitor works just fine... just not at the specified spec, I would find it incredibly surprising if that difference would break anything.

[harkaz]

I don't know the lane routing, just pointed out the difference.

Apart from that, it can be a problem with the monitor or the GPU.

UPDATE: Check for VRAM errors with tools like mods.

[PorcGras]

Maybe its worth to note: I have a secondary Aorus FI27Q monitor that runs just fine at QHD 144Hz. Not sure if that changes anything tho

[harkaz]

It indicates that GPU VRAMs are most likely working fine on other display routes. Apart from physical damage of the lanes connecting the MXM to the eDP connector on the motherboard, which can be inspected under microscope, it can be incompatible cable/LCD issue.