I've been using my PC normally, but when I turned it on, roughly half of the monitor was covered in colorful RGB lines. I can still move the mouse through the affected area. I tried two different HDMI cables and saw the same problem with both. However, when I connected the monitor to my Xbox, the display looked normal. What could be causing this, and how can I narrow down whether the problem is the GPU, monitor port, drivers, or something else?
3 Answers
Try connecting the monitor to another output first, and if your processor has integrated graphics, remove the GPU and connect the HDMI cable to the motherboard’s video port. If the lines disappear, that strongly suggests the graphics card or one of its ports is the problem.
Before replacing hardware, try reinstalling or updating the graphics drivers and testing a different monitor or cable output. Reseating the GPU is worth doing too. RAM or a faulty RAM slot can sometimes cause visual corruption, but the GPU is the more likely cause here.
A different port on the monitor is a useful quick check as well. If every monitor input works with the Xbox but the PC still produces lines, focus on the GPU, its drivers, or the motherboard slot.
This points more toward the PC’s graphics card or its connection than the monitor, since the Xbox displays normally. Power the PC off, remove and firmly reseat the GPU, then check that its power connectors are secure. If the issue remains, the GPU may be failing.
Testing another monitor would also help rule out a damaged monitor input, but the fact that the Xbox works normally already makes the PC side more suspicious.