I have problem with my iphone 6s 64gb, i bought it last year in february. I remembered the battery was full when i left the house, couple of hours i heard notifications coming in then when i was about to check the display screen turned black and i tried to turn it on but it wont start. I tried to press the home and power button for 20secs but still it wont turn on, i even connected it to the itunes on my laptop and it's not been detected. I tried to charge for an hour and still no sign of apple or battery. I brought for repair then the person who tried to fix my phone said the battery is still fine, the AC adapter and memory too, he mentioned about motherboard, is this problem possible to do with the motherboard? I have never overcharged my phone from night til morning and it never fell or cracks. I just dont know the problem if any of you know please do share. It just shut down without my consciousness.