LCD darken

LG W1942T is the 19-inch display.

Playing games (Dynasty Warriors 5) when suddenly cut out and then cut into the game.
If the game screen in a dark place where the display becomes Darker.
If it is a little light in the place where the normal.
Theater in the mode that is the case.
Network in the mode for the time being have not found such a situation.

Summary Is about:in the dark, but you cut out when recently re-cut it after dark more than you .!!!

display was bought two weeks ago.
Aging does not exist.

in the end what is the problem?
energy?

is estimated to monitor the aging