Chosen Solution
I replaced the battery on an iPhone 8 (ifixit battery) when I start up the phone, everything appears to work but after some time the phone gets hot - realy hot. I’m not sure where the heat is coming from and I don’t want to open it up again unless it’s really necessary.
Hi If it’s heating up I would try a and reseat all the connectors you disconnected and clean them with isopropyl alcohol while you are there As for finding the fault so would get a microfibre cloth and dip it in isopropyl alcohol not so it’s dripping by enough Then wipe the device and see where the alcohol evaporated first as that will point you to where it’s heating up and you can address it accordingly Hopefully this helps Thanks:-)
