Distorted or skewed image on the monitor
A monitor or other display with a distorted image can be caused by a many different things. Below is a checklist of steps you can follow to determine if the problem can be fixed or if your monitor is bad.
Tip: If your monitor screen is black, see our No display or black screen on a computer monitor page for steps in solving this problem.
Restart your computer, if your monitor looks fine until it starts Windows, you are encountering a video resolution or other driver issue. Make sure your video drivers are up-to-date and that your resolution is not too high.
Loose or defective cable
You may receive a distorted image when the cable is loose or defective. Disconnect the video cable (usually a DVI, VGA, HDMI cable) going from the back of the computer and verify that no pins are bent, burnt or broken. Once verified re-connect the monitor cable.
A distorted image can be caused by magnetic (EMI) or other interference. Verify no speakers, fans, or other magnetic devices are close to the monitor.
Refresh rate issue
If you have an older CRT monitor, the refresh rate is not properly set the monitor may have a wavy or an appearance that lines are going down or across the monitor slowly or fast. An improper refresh rate may also cause a flickering effect.
If the above suggestions have been checked, it is likely that the monitor is defective. To verify if it is the monitor connect the monitor to another computer. If the monitor has the same distortion on another computer, you have a bad monitor. If your monitor works fine on another computer, there may be a problem with the video card in the computer.
Note: Connecting your possibly defective monitor to another computer will in no way harm the other computer.