Chosen Solution
So, recently I bought a couple of broken iPhones from the internet and one of them is working just fine except that I keep getting that annoying message all over my screen about my iPhone needing to cool down. I’ve replaced the battery and even moved the logicboard to a different, working iPhone and the issue is still there. So it’s either a problem with the logicboard (which I find unlikely) or software. Any ideas? (btw, It’s not even getting much hot at all).
Is your iPhone getting very hot? If so, there’s some sort of issue with the board that’s causing it to heat up to the point where the phone is considered unsafe to use. If it’s not heating up, just giving you an annoying notification, then there is likely some sort of issue with the temperature sensor on the board. Does the inside of the phone have any clues as to if it’s been water damaged before?