Since a few days the phone of my girlfriend (a SONY ERICSSON XPERIA Z3 dual) had all kinds of problems including the notification sounds totally gone.
I solved the problem without losing any data!
I solved the problem without losing any data!
I remebered that years ago I posted on this blog (www.zibri.org) about a way to solve another problem (my phone was not going to deep sleep anymore) and I found out that just resettings a few settings it solved the problem,
I used the same method to solve a lot of situations including this.
The reason why this hapens is that some phone settings get corrupted with time (freezes, battery removed abruptly or jusyt software glitches).
The simple way to solve this it to enable USB debugging mode and connect to the phone using "adb" (android debug bridge) utility.
Then issue the command adb devices (on the phone a popup will appear asking you if you want to authorize this operation.
Once authorized, all you have to do is issuing 3 commands (probably only one of these is needed in your specific case, so you can try one by one or all together).
Then issue the command adb devices (on the phone a popup will appear asking you if you want to authorize this operation.
Once authorized, all you have to do is issuing 3 commands (probably only one of these is needed in your specific case, so you can try one by one or all together).
from your computer shell, write, one line at a time:
adb shell pm clear com.sonyericsson.customizedsettings adb shell pm clear com.sonyericsson.settings adb shell pm clear com.android.settings
every time the phone will answer with "Success".
then issue the command:
adb reboot
and all your problems will be solved 
