Chosen Solution
My Iphone 7 plus turns off as soon as i unplug it , i thought it needed a software update but whenever i try to plug it in the laptop and connect it into itunes it just enters in an endless loop mode. (The apple logo shows then turns off constantly , it also happens sometimes when plugged into the wall) When itd turned on it works normally. Note that it has fell from me before this started happening, but didn’t happen directly after falling. I need help to know what would be the reason this is happening.
The description you have described is commonly caused by a faulty battery. Replace the battery and it should be fine.
