no signs of life other than iTunes recognition after screen repair

done this repair as normal. ive been fixing phones for 4 years now and i got this iphone 6 that has no signs of life ie; doesn't vibrate when charging or when mute is toggled or when touch id reads wrong finger. only sign of life is it is detected by iTunes. i done everything correctly, did not mix up the screws tried changing the battery, and charging without battery plugged in with no luck. the tape around the connections is still present so there is no interference with the connectors and logic board fuses. need help please