This step shows how to reconnect the proximity sensor during re-assembly.

Align the top edge of the plastic midframe with the phone.

Use the point of a spudger to carefully align and push the proximity sensor connector onto the motherboard socket.

This takes a bit of patience and finesse. Once you have the connector in place, you can also use a finger to gently press the connector onto the socket.

Alternatively, you can remove the proximity sensor from the midframe to reattach it to the motherboard first.

Use the point of a spudger to carefully pry the proximity sensor out of its recess on the midframe. The sensor is lightly adhered to the midframe.

Remove the sensor from the midframe. Attach the sensor connector onto its motherboard socket.

Thread the sensor cable through the midframe and reposition the sensor in the recess. Press down with your finger to adhere the sensor back onto the midframe.