If your computer monitor is not displaying correctly, there are a few steps you can take to try and diagnose the problem.
First, make sure that all of the necessary cables (power, video, and audio) are properly connected to both the monitor and the computer. It’s also possible that the cables have gone bad, so if no other solutions work, consider replacing them. Make sure the video cable is securely plugged into the monitor’s video port as well as the computer’s video port/GPU slot. If you are using a DVI or VGA connection, make sure the pins on the plugs aren’t bent and that the cable is properly plugged in. Many computer monitors also have an on/off button or switch on the back side, which should be turned on or switched to the correct position.
Second, check the monitor’s settings. Some monitors come with menus where you can adjust the display such as brightness, contrast, sharpness and more. These settings can be controlled by buttons on the monitor itself or through the computer’s software. In addition, check to make sure the monitor’s resolution is set correctly – the wrong resolution may cause odd display issues.
Third, check the computer’s display settings. On Windows machines, go to the Control Panel, click Display and then click ‘adjust resolution’ to bring up the settings. On macOS, click System Preferences then click Displays. Make sure the settings are at their default levels, as you can always adjust them later if needed. Additionally, make sure the monitor is set as the main display device.
Fourth, check the video card settings. You may need to install or update the video card drivers, as out of date or incorrect drivers can cause display issues. You can check the manufacturer’s website for the correct drivers. After installing the correct drivers, check the settings on the video card’s control panel if it has one. You may need to adjust settings such as brightness, contrast, color settings, and other settings.
Finally, if none of the above solutions work, the issue may be due to a hardware problem. The monitor may need to be replaced, or the computer’s GPU may need to be repaired or replaced. Check with the manufacturer to see if the monitor or GPU are still covered under warranty. If they are not, you can try testing out a different monitor or GPU.
In short, if your computer monitor is not displaying correctly, the first steps to take are to check the cables and the settings on the monitor, computer, and video card. If these steps don’t work, then you may need to replace the monitor, GPU, or both.