My ringtone and notification sounds were working perfectly until I tried creating my own notification sound out of a youtube video I had converted to (I believe) an mp3 file. It was unsuccessful, so I switched back to my original notification sound, which I found on the Zedge app. Since then however, whenever I receive a message, the phone vibrates but makes no sound at all. It is NOT set to silent, and both the ringtone and notification sound volume are turned up. I have deleted all of the notification sounds I was originally using from Zedge, and re-downloaded them, but still nothing.