回答“Touch screen problems after screen replacement”Ok, so WOW....I solved the touch playing up after several screen replacements on one customers iPhone 5S. After throwing 3 screens in the trash thinking I had a bad batch it was something so RIDICULOUS it's not even funny. The LCD shield plate (where the black soft material is on the right side) had a scratch in it that was exposing the metal underneath. Just on a whim, I covered it with a small piece of Kapton (Polyamide) tape. Voila! The theory is there was static electricity build up causing intermittent touch malfunction. This soft black covering must protect from that. This problem seriously was about to send me to the psych unit! See pics...