So i got this thing used a couple days ago, and the first few days it worked ok, but then yesterday i couldn't get it to display my screen for some reason. I wake up today and it works again, but then i leave for like 5 minutes and when i come back, the colors look super wierd, and it displays black as this greyish color, and there are these vertical lines as shown in the picture. Furthermore it started to burn in windows that i had open for like 1-2 minutes, as well as the settings panel in the bottom right, so that they are clearly visible even while nothing is plugged into the monitor.

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I haven't managed to find anything similar by googling, does anyone here have any idea what this could be? Any help would be much appriciated, ty