After John updated his iPhone 5 to iOS 9.3, it's not doing anything. AT&T says that Apple has been having issues with the update and that he needed to contact Apple. So after 2 hours of backing up, reloading, etc. Apple determined it was a hardware issue and that he should buy a new phone. Leo says that one last thing he can do is take out the SIM card and then put it back in. Sometimes it can shake lose.
John wound up buying a new iPhone 6s through a 'buy one get one' deal for him and his wife, but now he's getting terrible battery life on one of them. It's only lasting about a half day. Leo says John's wife could have different usage patterns. So they reloaded it and it's still not holding a charge. Leo says it sounds like a lemon, and because Apple sells millions of phones, a certain small percentage will have issues. Leo says that since it's under warranty, John should keep taking it back until they replace it. They should because that's what it needs.
Could an OS kill a phone? Leo says no. It could cause those problems, but not destroy the hardware.