Windows 8 Monitor trouble

So, my computer was working fine. I leave my room to get something, come back and my cat is on my keyboard. I shoo her away and try to wake my computer up but when I get my monitor to turn back on, all I get is the monitor's test pattern. I've disconnected and turned everything off and then reconnected everything and I'm still having the same problem. Could there be some kind of keyboard shortcut that would have done this? I already tried the input switch shortcut (windows key + ctrl + space bar) and that didn't do anything. Please help!

Try connecting the monitor to another computer, if you can. Just to verify that the problem is not the monitor or the cable.

It's quite possible your monitor may have died coincidentally at the same time.

Another possibility is that your cat somehow triggered the display dialog and managed to choose a resolution that is invalid for your monitor, and the monitor is showing black.

When you reboot, does the monitor come on and show the power on screen?

Use the monitor built in menus to reset it.