I've just bought an Iphone 6s for about 3 days now. At first It restart randomly, whenever I'm not using the phone (idle). Last night I left It at about 90% battery, and I found out this morning that My Iphone has died, and Hard-resetting won't do anything to it. When I try to put it into recovery mode and plug it into my PC, The Itunes detects my phone but the Iphone screen still went black. Please help me on solving this problem. Thanks!