Pictures comes out black on Nikon D3100?

I have a Nikon D3100 which I purchased nearly a year ago. It have been working perfectly until yesterday. I had been taking a few pictures and I could see them perfectly clear on the screen after I had taken them, but then the next picture I took came out all black. I can still see the previous ones I took, but now all pictures comes out black, the flash is working, it's making the sounds it should and the date is on the pictures, but the image isn't. I've tried to recharge the battery but nothing happens. I've taken of the lens and still nothing. Does anyone know what's wrong and what I can do?

Have you tried to reset Factory Settings?

If not take the camera back to Nikon for a service.

Pictures that come out black are very under-exposed. Is it possible that you accidentally changed the aperture on the lens to f16 or f22 or f32? Even with flash such an aperture setting would cause under-exposure.

This video tutorial may help you:
http://www.nikondigitutor.com/eng/d3100/index.html

It may be necessary to send your camera to a Nikon Authorized Service Center. There should be a list in the back of the Owner's Manual for your camera.