If it isn't under warranty (as you don't want to void the warranty) I would try opening it up and making sure the cable for the screen isn't loose, damaged, bent, etc. This can cause the problem you are having.
You should also consider updating the drivers for the display.
If it persists, try turning off the laptop and attaching an external monitor. Power on the external monitor first, and then once is it one turn on the laptop. See if the problem happens with it. If not, and the cables were fine, then the attached display may be going.