Here is another solution for another irritating problem. The issue is seen to occur on iPhone 6 , iPhone 7 and iPhone SE , when the device is updated to iOS 11.1.2 .
As reported, when iPhone 7 , iPhone 6 or iPhone SE is updated to iOS 11.1.2 , it’s keeps on switching on and Off. Which is really an irritating problem. It will show a dark black screen and sometimes it gets lock into lock screen. So here we have got the fix or say solution for it.
First goto Settings > General > Update and check for new update , if available update to latest version that is iOS 11.2. But if you are unable to update. You have to set the date back to end of previous month. Say example now it’s December and I’m facing issue to update. so, what I have to do is change my device date to November 30.
In this way you can easily overcome this problem of switching off and on iPhone.