dell e6400 sudden shut down

I was converting some video on a dell e6400 laptop when it suddenly shut off and would not power back on. I tried removing the battery and reinstalling it and unpluging and plugging it back in. It was in a warm room when it quit. Now I have no power at all to the laptop and it wont respond to anything at all . What could be causing this power source issue? It had no problems until now.