If the battery is completely drained, the phone may not respond immediately.
Often, the phone is powered on but "frozen" with a black screen. A force restart can jumpstart the system. iphone-6-no-power-solution-100-working
Plug it in for at least 30–60 minutes before attempting another force restart. If the battery is completely drained, the phone
Use a toothpick or compressed air to remove lint from the charging port. If the battery is completely drained
Go to product viewer dialog for this item. that won't power on, start with simple software and external hardware resets before moving to advanced board-level repairs.