Touch only responsive sometimes.

An iPhone 6 came to me where someone had paid a friend to replace the screen and about 4 months after the replacement the screen no longer responds to touch. I tried 3 different replacement screens and I am still having the same issue. Although after restoring the iphone software the touch will work intermittently and sometimes phantom click. I have looked at and cleaned all of the connectors but still no luck. There is a couple small indention on the back housing where the phone has supposedly been punched by someone. I took the board out and looked it over to see if there had been any damage and could not find any.

Any ideas or solutions would be greatly appreciated!

Thank You!