It just happend yesterday, and I noticed that i already had put it on vibrate, but it doesnt. The sound comes up , but i need it to vibrate because I can't really hear the ringtone when im in a loud place. Usually, when i set it vibrate ON, it vibrates 3 times so it can let me know it works. But that doesn't happen anymore too. How do i fix this? I tried shutting it off but that doesn't work .