Hey there Scott and welcome to PCHF,
Make sure that your monitor is plugged in firmly, some things you can try to test if your monitor is faulty are listed below:
- Tap the side of the screen, LCD's might not do it, and see whether the screen flickers whilst you do that
- Play with the monitor cable that connects to the video card, once again you might see flickering.
- Lastly try plugging another monitor on to your computer, if this one works properly then you know your monitor is on the way out.
Have you changed any video card settings recently?
- Open display properties and reset your resolution to something like 1024x768, then change the refresh rate to 75, see if it carries on messing around.