WHY WON't MY CAMERA TURN ON

I have a nikon bridge camera, my camera has been working fine lately and i've never had any problems with it before, today i plugged it into my laptop via USB but when i unplugged it after 2 hours or so it just wouldn't turn on at all, my batteries are full and i've never broken it or dropped it it just won't turn on i have only had it since june

If you tried to charge the batteries via laptop - that won't work. Cameras are not like iPhones, most of them will not charge when connected to a USB cable. The only cameras that can do so that I'm aware of are some Olympus cameras.

If you have a L120, you got to replace batteries every once in awhile. They are not rechargeable (unless you bought rechargeables).

http://www.althephoto.com