Nikon D300 Nothing in Viewfinder or Control Panel

My camera is only 6 weeks old and I've been having this problem for about 4 weeks. The camera is off and it looks as though the battery is dead except for there is nothing in the control panel denoting the need for changing the battery. Then when the camera is "on", still nothing is in the control panel and when I look through the viewfinder all that is shown is a fuzzy grid. This grid appears with a lens attached and also w/o a lens. Sometimes if I take the battery out and put it back in, the camera will switch on and look as if there is no problem at all. But sometimes it needs a charge, but generally it is a fully charged battery. I have never had to recharge my battery because the blinking at me. It is only because of this weird problem.