Your explanation isn't very clear as to when the screen doesn't work.
I've heard issues with dodgy chargers preventing touch screen from working whilst plugged in.
If the touch screen doesn't work when no cables are plugged in, it's probably just broken.
There's a service menu you can get to with a touch screen test, I can't remember how to get there, but it also has a battery test if that makes it easier to search for. If that test fails when no cables are plugged in, it's time to get it repaired.