Hardware

If the screen is showing green dots, then it could be due to faulty graphic card. You can also try changing your screen configuration or if you are using any HDMI cable make sure that it is properly connected to graphic card. If that isn't working as well then you should consult some expert about the problem, as it must be a more of a technical issue. Thanks!

Try to use another monitor or a different cable to see if the same thing happens.