Hi there. Sorry if this is a done-to-death topic, but the sound on my iPhone 4S no longer works. It happened without a trigger. I was listening to the TuneIn Radio app. One moment it was fine, the next it was broken. YouTube does not work with sound either, although alarms and phone calls do work, which I thought was strange as it comes out of the same speaker. I have tried the obviously remedies in terms of restarting the device and clearing the speakers from dust etc but have had no success. Any help would be much appreciated. Thanks in advance.