have you downloaded / read the manual yet on this situation ?
how to do various resets
Camera needs to be reset
If your LCD screen randomly dims or darkens during use, attempt a factory reset. Navigate to menu selection screen by pressing the [Menu/Set] button at the center of the control dial. Use, the control dial to move left, right, up, and down to select the [Setup] menu then press the [Menu/Set] button. Select the [Reset] command then press the [Menu/Set] button to factory reset your camera.
Camera requires a reset
If you don't think that debris could have gotten into your lens, then a possible solution is to reset your camera. Turn off your camera and take out the battery. Let the camera sit for 30 seconds and put the battery back in and turn on your camera.