my girlfriends iphone 3gs 16gb ran out of battery last night and she plugged it in to the car charger for about 20 mins and it didnt turn on. when she got back to the house we put it on charge for around 10 hours and it still hasnt turned on. anyone know what the problem could be? EDIT: It isnt the charger as i have tried other ones and they all charge my iphone 4 and ipad. it also doesnt have the battery/ lightning bolt on the screen, its completely black. i have tried holding down the two buttons to reset.