1. Uninstall Apps to Resolve the Touch Screen not Working Issue
2. Restart your iPhone – Software Restart or Hard Reset
If you are unable to restart your phone with its touch screen, press and hold power and volume down button at the same time.It will restart your iPhone in few seconds.
3. Restore iPhone to Factory settings
4. Restoring with iTunes
Connectting the Iphone 7 to a computer and open iTunes. On the Summary pane, a person can select. Restore. If the phone does not appear in iTunes, there's not much you can do yourself at this point, but you can still get it fixed or salvage the value of the phone.
In ordinary life we should care our iphone, and know the reason about iphone screen.
1.Too many programs running at the same time causing memory issues;
2.Faulty primary or secondary touch screen control IC;
3.Dry soldering of touch screen connectors;
4.Touch screen got physically damaged;
5.Accumulation of dirt or grease and foreign materials on the screen;
6.Don't touch the screen of iphone 7, if your hand are wet;