Chosen Solution
it is not shutting off. i tried doing a reset on it already
There is a short in the charging port. Clean the iPhone charging port very well with toothbrush and isopropyl alcohol. If still problem, replace charging port assembly with flex cable, lower mic and connector for home button flex cable, all a single part. Most people leave their iPhones ON 24/7, so just leave it ON like most others.
Could be a fault in the power flex cable you can test this by opening up and disconnecting the power flex cable then power device up by using the charger then power device off. If it stays off its the power flex cable that’s giving you problems
