Chosen Solution
It seems as though the phone is off but it still makes sounds when it is connected to the charger or when the volume is turned up. Is there anything we can do to fix it?
Force a restart. There are two ways you can force a restart on your device: Press and hold the Power key (or Side key) and Volume down key for 20 seconds. On devices with removable batteries, remove the battery for 60 seconds, and then reinsert it. Regards, Will