Originally Posted by khumash
Where can I find the setting to turn on the notification sound when the screen is off (locked)? The phone is not muted.
Is it only the sound which is missing or do you not get notifications at all?
If it's only the sound, individual apps have their own settings for notifications, but it'd be odd if all of them have them turned off.
I guess it's more likely that the phone disconnects from WiFi when idle. This can be fixed through settings -> wifi -> advanced -> keep Wifi on during sleep: always.