Chosen Solution

Monitor: Acer XV240YThe monitor was fine when first bought, the max it can run on original spec was 165hz but then slowly, the monitor appeared to have a weird horizontal glitching lines similar to this (refer to the link) MSI Optix MAG24C Horizontal Lines I never did anything to the monitor before, it just starts getting more and more glitchier so I had to switch down to lower refresh rate which were 144HZ but then after some times the thing happend and I kept switching down till 85HZ which I am still at rn and it stopped at 85HZ. I’ve tried switching out the input cable from DP to HDMI and it still has the same problem, even when switching the power connector still has the same problem, and it’s not the PC’s fault aswell because I tried it with a laptop aswell and it was still the same so it has to be the monitor. I’ve asked so many people about it and they had no idea and the link above is the only one that I found that have a similar situation to me.

https://www.reddit.com/r/Monitors/commen… here’s the video of how it used to look like when it first started out

cocok97 this is not related to any of the scan rates. Those horizontal lines are failures of your Gate Drivers. We would need to know what panel your monitor uses, as well as seeing the LCD driver boards. Post some good images of the boards, which are connected to the LCD panel via very thin ribbon cables, with your QUESTION. Those boards are not removable because of the way they are bonded to the panel. Adding images to an existing question - iFixit Repair Guide

Have you tested to ensure this isn’t a GPU problem. It doesn’t seem likely but ALWAYS do the simple things first. Plugging in a friends monitor of high refresh rate will rule that out. If its good then…An educated guess here would be the controller for the monitor may be dying. The monitors like your PC have a “CPU” and they can fail. It may be a re-driver (used on devices to set screen resolution and refresh rate) issue for the screen or some type of TCON style controller. The main problem here is it may be a hardware issue that would require a board replacement.