Warning: Do not attempt to troubleshoot with your eyes closed, as this may result in unnecessary frustration and/or blindness.
Step 1: Turn your monitor off, then turn it back on. Repeat this process several times until you're convinced that the screen is not, in fact, a sentient being attempting to communicate with you in a series of cryptic error messages.
Sub-Step 1: Check your power cord for any visible signs of life, such as writhing tentacles or a faint glow of malevolence.
Sub-Step 2: If the cord appears lifeless, try turning off your monitor, then turning it on again. And again. And again. And one more time, just to be sure.