For the past month or two, my display has intermittently developed black lines and large patches of white lines. The problem used to disappear after several hours and stay away for a few weeks, but recently it began lasting for days. I bought a new Koorui monitor, yet the artifacts still appear. I also removed and reinstalled my display drivers with DDU and tested multiple HDMI cables. When I connected the monitor to a different laptop, the same distortion appeared, so I'm unsure whether the problem is the monitor, cable, graphics hardware, or something else. Is there a reliable way to diagnose or repair it, or should I replace the monitor again?
3 Answers
If the same lines appear with different cables and on another computer, the monitor itself is the strongest suspect. It could be a bad panel, internal display wiring, or controller board. Those faults generally aren’t practical to repair, so replacing or returning the monitor is probably the sensible option.
Try the monitor’s built-in menu or no-signal screen. If the lines are visible over the monitor’s own menu, the panel or internal wiring is defective. If the menu is clean but the computer image is corrupted, then focus on the graphics card, video output, or cable. Given that you already tried multiple HDMI cables and another computer, a faulty monitor remains very likely.
Artifacts can also come from a failing graphics card, especially if they appear before the operating system starts. A useful test is to capture a screenshot and view that file on another device: if the lines are present in the file, the GPU is producing them; if the screenshot is clean elsewhere, the monitor, cable, or its internal electronics are responsible.
The artifacts are visible during startup, and the captured image seems to contain them as well. Since the same issue appeared when testing another laptop, I’ll verify the screenshot on a separate display before deciding what to replace.
The distortion also shows up during startup, before the operating system loads, so I’m leaning toward a hardware problem rather than a driver issue.