Chosen Solution
I just replaced iPhone 5s complete display assembly, screen comes on but touch functions do not work at all!, can’t even shutoff phone. What could be the issue?
I would strongly suggust check your connections to make sure you have a proper connection and to see if there is any obvious damage to the flex able. If one connection is loose, this can cause touch issues. You can also clean the connection with a toothbrush. If all this fails, I would try your old screen or another screen to see if it is a screen issue. If so, contact your representative about the issues you are having with the replacement screen.
Check output voltage sage u3, if normally replace u15. If u3 heat replace u15
