Share your experience!
When am playing music, my Sony Xperia z suddenly turns the sound off and I cant turn it back up. even when I use the volume button and when I go to settings and try to turn the media volume up, it still doesnt work until I turn off the phone and turn it back on
perhaps you should repair your phone
Update Service (SUS)
http://www.sonymobile.com/gb/tools/update-service/
http://www-support-downloads.sonymobile.com/Software%20Downloads/Update_Service_Setup-2.11.12.5.exe
Bridge (for Mac)
Alternatives on How to backup Xperias
http://talk.sonymobile.com/thread/36355
Don't forget the Kudos