Chosen Solution

So I have had this iPhone 5s since it first launched, and the batt died last August. Got a battery replacement mid December. Problems:

  1. The phone would mysteriously die when not in use. In 24 hours it’ll for sure turn off by itself. Over night it’ll shutoff. Keeping iPhone plugged in doesn’t solve the problem, it’ll still shutdown.
  2. When around 20% batt left phone would shutoff, when plugged in will turn on again normally.
  3. Changing to another batt didn’t solve the problem. I bought like 5 replacement batteries, none of them fixed the problem, tried them on my other 5s as I have about 4 of them, worked perfectly fine, no random shutdowns. Question: Which ic chip is most probably busted? Main power IC or the U2 chip? Or is it something else?? PS. In diagnostic there is Panic code Update (03/07/2017)

@benjamen50 which one? the one @ the very right?

Power management IC no doubt. U2 Tristar Charging IC does not cause this.

Before you go into the motherboard troubleshooting I would suggest that you charge the battery up to 100%, open up the phone, disconnect the charging port and proximity sensor and see if it still shuts off. If the problem is gone then re-connect the parts one by one until the problem re-occurs.

My iPhone switches off when I lock it or when it’s go to sleep mode and for me to use it the screen must be on all the time please help

i would send it to the store you got it from and see if they can do anything about