Nokia Lumia 520 won't start after the start screens come up.

My Lumia 520 is on the start screen where it says Nokia and then there's the AT&T symbol. It goes back and forth between them and just won't turn on. I've tried resetting my phone already. It just won't turn on past the start screen.

from Windows Central Forums http://ift.tt/29tpZdE
via IFTTT