Chosen Solution
My iPhone 6 would suddenly die when there is still definitely a battery in it. It won’t charge or turn on or become recognised in iTunes. However, usually the next morning when I try turn on the phone, the no batteries screen would appear. This has happened twice in the last 4 months. However, last night the phone turned off again and now won’t turn back on.
Try a new battery, when plugged in does it show its charging ?, if not try another charge port. If still no go its probably going to be the tristar chip.
