Don't know very much about monitors but.
-Try pulling out the power and reconnecting it.
-connect the video cable into a different slot in the screen and change the source.
-Check all the cables are secure.
-Try switching whatever (HDMI, VGA, DVI) cable you are using maybe its damaged.
-Try resetting the screen to factory defaults.
-Try the monitor with a different pc or somthing.
-Call Asus support or email them and ask.
Hope it works.
Sorry i'm not very good with monitors but when something goes wrong with my screens i usually do one or more of the steps above.
-Try pulling out the power and reconnecting it.
-connect the video cable into a different slot in the screen and change the source.
-Check all the cables are secure.
-Try switching whatever (HDMI, VGA, DVI) cable you are using maybe its damaged.
-Try resetting the screen to factory defaults.
-Try the monitor with a different pc or somthing.
-Call Asus support or email them and ask.
Hope it works.
Sorry i'm not very good with monitors but when something goes wrong with my screens i usually do one or more of the steps above.