How old is the phone?
Is it over or under 1 year? It is important for warranty purposes.
Okay try this first..
Connect the phone to a charger
While it is connected, hold down the POWER button for 30 seconds without releasing and the phone should restart.
After the restart, try again.
In that case, the phone has hardware failure. The good news is that your phone is still under warranty so it can be replaced.
Please call 1-***-***-**** and let them know that your Galaxy Mega 2 is having hardware failure.
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