My first thought was to return it. If it's under warranty, and already causing you grief, chances are it won't get better over time. Take it back!
If it works normally sometimes, but blacks out at other times, I would not suspect a setting as a culprit. It should be set to work out of the box, and if you didn't mess with the settings too much, chances are you didn't cause the problem.
My 2 Cents...