If the four buttons are dim, and flickering, you will need to allow the phone to charge, this is a sign that you exasted the battery to the fullest. Youll see not asingle thing but te four buttons.
1 take back cover off, Pull battery, and pull Sd micro card out, count 10 secs
2. replace all back in, and AC wall charge, allow a good 7%, 30 minutes.
3 turn on phone , long press top right Button 3 sec hold or so.
The Phone will not run at all with no battery, and that I have had the same problem, it is not a issue.
If you still cannot get On then you'll have an Option to go into Sprint, have them place another battery in, if turns on
Battery is defective.
If not a thing. possable part gave out.
they'll replace your phone for freee if under 14 days-30 days brand new.
We'll give you FREE advice for lifetime here. hope we helped out.