Chosen Solution
This is probably the THIRD iPhone 8 or 8+ that has had this issue. Even though we were careful to remove the camera flex cable and the tape with it, and transfer it to the new LCD/Digitizer assembly, the earpiece REFUSES to work. The camera works just fine. I need assistance and answers. I have cleaned the contacts with alcohol. I have installed Kapton tape. I have switched out the piece with a new flex cable and new ear piece speaker. Yet, I know it worked BEFORE we took the phone apart. Suggestions on how to use the ORIGINAL flex cable?
You want to make sure that the metal bracket that covers the earpiece and speaker is properly aligned, and none of the tiny springs on the receiver are bent or improperly seated. They should all evenly be pressed when the bracket is screwed into position.
