If your ball point pen is dead, it's usually because the ink has dried above the ball and locked the ball in place. If this happens, some things you can try to revive your ballpoint pen are:

1 - Tap your pen repeatedly on a hard surface to try and jar the ball loose.

2 - Spray window cleaner on your finger and rub the ball of the pen with the window cleaner. This should loosen up a stuck ball. Get the ball good and damp and then scribble vigorously on a piece of paper to work it in. If your pen is not out of ink, this will almost always fix it.