This will sound absolutely ridiculous, trust me I thought it was. My daughter tried everything she could find online & had given up a week prior to me fixing the issue clean debris, hold power button & home button, different charging ports ,etc. .. I literally switched her vibrate button on the side back & forth a couple of times & the phone began charging right up .
It won't fix everyone's but it can't hurt to try. I still can hardly believe it was that simple.