The problem with the screen after update.

Good afternoon.

Please tell me, I have an iphone 5s, I have updated to the latest version of ios, I have an incomprehensible error, with a strong tap on the screen it stops working, before this problem was not. You can help, I don't want to change the phone, it's a gift. The phone did not fall not "bathed" not any mechanical damage, and no overheating was not, charging only the original, the original battery, but keeps bad! Thank you!!!!!