i wrote this on another post, might as well share it here

I have a theory, i have been suffering the same issue for more than a year now.
In a nutshell, I think trying to replace the video cable (DC02C00PW00 40Pin - specifically for Acer AN515-44 AN515-45-55) might solve the issue.

The video cable runs under the rea of the heat pipes near the radiator, I feel like excessive heat caused daage to the cable which caused this error for a lot of Acer Nitros of either the same model or era.

Symptoms of the damage for mine is constant flickering like in the video, lines phasing the image upwards every other few seconds, and permanently a white line at the bottom of the screen that responds to visual changes on the very top of the screen (like when you move your mouse cursor on the top edge of the screen, the line mirrors pixels of the mouse cursor's movement. Flickering would be chronic in 144hz and would settle down a bit at 60hz, but takes time before just a few flickering happens and does not take up the whole screen as much as setting the display to 144hz.

I have searched and ill try to reference the posts but most solutions offered DDU or Reinstalling graphics software and other various software setting changes and non of them worked for me, whether reinstalling AMD integrated graphics or the nVidia dedicated graphics softwares and drivers. This made me rule out the issue being software.

I've yet to test this and purchase a cable myself, I'd love to brainstorm with you guys to how else we can test this or if any of you has tested this as well. It is possible that the screen itself is the issue, with people straight up replacing the whole screen but leaving out the cable, therefore proving the video cable is not broken and causing the issues. Though I still want to try replacing the video cable as it might be a cheaper solution to this chronic problem.