Shutting off randomly, now not even turning on.
My 5s started randomly switching off a few months ago (would do so even on 99% battery), but would usually turn on again in a few minutes, and the problem went away.
But last week it started randomly switching off again, then started to switch off whenever it was disconnected from power. Now it won't even turn on when plugged in.
At first I thought it could be a battery issue, but the fact that it doesn't work when plugged in makes me this the issue lies elsewhere.
Any advice would be much appreciated.
Edit: should add that the phone is in good condition, well looked after, and when working normally has good battery life.
Is this a good question?