The monitor is one of the most important components of the computer, as this is how an individual can use his PC. Sometimes the monitor may come up with a few issues: it may even start flickering or show waves. This problem can come from various sources. It may be that the monitor is out of order or the source of power is corrupted or the adapter is facing a failure. It can also be due to disturbances from nearby electronic devices or the display may be picking up line noise. The problem can also emanate from a magnetic force in the vicinity. Once the user has identified what is causing the flickering or waving display on the monitor, he/she will be able address and hopefully solve the issue.
If you notice that your monitor has some sort of waves or is flickering, it could be down to a lot of things.
It could be:
1) Line Noise
2) Insufficient or corrupted power supply
3) Bad graphics adapter
4) Failing monitor
5) Electrical disturbance (from a device, such as speakers around your monitor)
6) Strong magnetism from a nearby source, and many other things
Steps to follow
Complete the steps in this order to find out what's wrong!
1 - Make sure all connections for the monitor are properly connected.
2 - If you have spare monitor adapters and cords, try using them.
3 - Plug the power cord of the monitor into a different outlet running off a different circuit in your home.
4 - Try moving any electrical devices near your monitor at least 8 feet away.
5 - Try using a certified, grounded extension cord for your monitor
6 - If none of this makes a difference, if you have a spare monitor try it.
7 - Make sure the GPU of your system isn't dusty and the fans are working.
8 - Try lowering the refresh rate of your monitor to 70-75 and setting the resolution as high as it can go, then restart the computer.
9 - If all this fails, it still may not be a problem with your PC as a whole, but bad electricity in your home. If you live near a switching grid, or some other high power station then this is a common problem in homes after heavy lightning storms. Your system will get shocked (surge protector or not) due to bad wiring and create corruption in the flow of electricity to your PC.
Try starting the PC up normally and once booted, abruptly hit the restart button. On the first screen shown as the computer reboots, abruptly hit the power button (not restart), and quickly hit the power button again to start the computer up. This isn't a permanent solution and isn't good for your PC's health if done a lot, but it solves the problem temporarily.