Help Locked up

[Zatsuya]

So I exited out of my pandora app and went to youtube and the phone froze. it started with a black square in the center of the screen, then the entire screen faded to an inactive black background. The phone is still on and so is the back light.

does anyone know how to fix the problem.
does anyone know how to rest the phone.

 

[whiteraven]

Have you tried removing the battery and putting it back in?

 

[AvaLucille]

A battrery pull or letting the phone die can fix all most anything