i had the same issue on my 3gs for about two days days and i realized that it might have something with a dock because its ringing when im receiving a call or a message and when i play music or open application there is no sound and my iphone had the same symptomes
so i tried a little test ive put my iphone on a dock and fastly put it off and played some song and it played for a second or two but then it stoped and volume control banished
then i realized it must be something in iphones connector and used a toothpick and gently cleaned out dust and dirt that was in and then i put my iphone in and out of dock and after that my sound works fine, i hope this helped you at least a bit
I have the same issue as Atoidi - "...youtube and play a video, there is no volume, the volume buttons have no impact, and the volume control is blanked out when double clicking the home button." except that I have att version of the iPhone 4S iOS 5.1.1. Anyone has a resolution for this issue? Please help.
people i have same problem with my new 4s about 2 months and the solve for this problem is: use program IEXPLORER from internet and connect iphone then ,go to system , library and then "launch daemon" and delete com.apple.iapd.plist and problem are 100% solved after phone restart.tank'you and I hope I was helpful