Black pictures with my new Nikon D3100?

I just bought a refurbished Nikon D3100 and I took it out of the box, put the lens on and tried to take a test picture, and the picture is coming out black… It looked fine through the viewfinder, the lens cap is off, it's on auto (I know exposure levels etc enough to know that it's not just under exposed), and the screen works (the info shows up before I take the picture and at the bottom of the screen when I'm reviewing them)
I tried switching my lens to another one, and it's definitely a problem with the camera!
Is it something I'm not doing, or is it just a manufacturer's error?

Contact Nikon. My first thought would be that the camera's on Manual, but if that isn't the problem, check that the lens is properly mounted (red dot to red dot - twist until you hear a click) and consult your manual.

If you don't have a manual, download one from Nikon NOW.

Call Nikon As soon as possible 800. NIKON-UX

If you are using the camera correctly, you should not get black image files.

Did you try auto mode outside in the bright daylight?

Although you did not specify, I'm assuming your lenses are AF-S (so they are auto capable). But if they are, auto mode should not let you take a photo unless the lighiting conditions are within acceptable.

Since you know metering - does the metering show the correct exposure?

And finally, make sure that the exposure compensation is set to 0, and not -3.

You should have a 90 day warranty. I would return it if it is not working.