Lumia 720 screen doesn't start.

[Windows Central Question]

I've got a nokia lumia 720. Today suddenly the phone screen stopped showing up anything even though the capacitive buttons were lighting up. When i connect the phone to the charger and try to power on or reset, the phone vibrates once in a while and the three buttons light up, but nothing happens after that. When not connected to a charger, the phone dosen't even light up those keys. No nokia care in my city, hence i desperately need help.