Share your experience!
Things to try
settings > about phone > diagnostics > test it
settings > apps > all > camera > clear data > restart the phone
or
boot on safe mode and see if it works
if it doesn't then repair the phone with PCC
Bridge (for Mac)
Alternatives on How to backup Xperias
http://talk.sonymobile.com/thread/36355
if that doesn't work then contact your Local support
Flashlight not working M4 aqua