Hello all - hoping someone can help. I have an iPhone I can't sync - iPhone 6 latest iOS and latest iTunes on Mac. Phone charges and behaves fine, using genuine lightning cable. But if I plug into USB on my Mac nothing happens. Doesn't even charge. iTunes sees the phone for wifi sync but the sync always crashes. USB port works fine for other hardware. Spent a day moving music etc to another computer, set up iTunes and went to sync to this machine instead and the same thing happened, so I can only assume the problem is with the iPhone. Any suggestions apart from total reset and start again?