Nokia Asha 503 hard reset

  It is very easy to hard reset Nokia Asha 305.You don't need any knowledge to do this.Just read this post.
  Warning! All user data will be lost so please make backup first.
  Power on your phone.
  Type on screen keyboard *#7370#

  Confirm OK!

That's all!

For more details please watch here the entire video tutorial:https://www.youtube.com/watch?v=JjoKbZNlKu8