Hey,
So sometimes, when I watch a youtube video, vine, or anything of that sorts my main monitor will either turn blank, have lines going across it and stuff. I've messed around with the display properties and if I swap the displays between monitor 1 & 2 the effect transfer to my second monitor.
Sometimes if I close the video down it will be working fine again, sometimes I have to completely reboot my PC. Any help would be swell.
Make sure that the monitor plug is perfectly in.
Try to test the monitor with another computer to see if that's a computer problem or a monitor problem.
And, as usual, verify if your drivers are updated.
have you tried updating/doing clean install of graphics drivers?
I think I had a similar problem a few months ago
http://teamfortress.tv/thread/20213/monitor-freaks-out-when-watching-videos-sometimes
I fixed it by disabling hardware acceleration in chrome and flash. (Might have to google how to disable hardware accel in your browser if you aren't using chrome)
To disable hw accel in chrome, type chrome://settings in the search bar and hit enter. Click show advanced settings and uncheck "Use hardware acceleration when available".
To disable hw accel in your flash player, right click the animation in the link below, click settings, and uncheck "Enable hardware acceleration".
http://helpx.adobe.com/flash-player.html#main_Find_Flash_Player_version_type_and_capabilities__Flash_developers_only_