what it do, everybody

my cuz sent me this great phone but the battery had problems so a decided to buy a new one, i ordered it, it arrived, but my cell won't turn on i don't know whats going on... because the phone is new an also the battery is new,i measured the battery and it has 3.7v so its full but the phone won't turn on even when its charging it doesn't show any signal of life,neither the screen nor the leds turn on while is charging..


if anybody has an idea of whats going on I'd appreciate the help

THANKS
HELP !!!!