How to fix an iphone when the touch screen isnt working?

I have an iphone 4g and recently the touch screen stopped working so i replaced the screen and this did not fix it and i have tried rebooting it by holding the lock and home button till its reboots many times also have tried restoring it and that did not work either. I would like to know if anyone knows a way i can fix it because if not ill just take it to someone

Samsung Galaxy S3 / S4