The communication board sends information about the aperture and focus of the lens. If you are having trouble with focus or aperture, then there may be a problem with the communication board.
Use a 00 Phillips head screwdriver to remove the four screws from the lens mount.
Remove lens mount from the camera.
Remove the three loose parts (spring, small rod, and metal ring) that were under the lens mount and put them aside.
Use 00 Phillips head screwdriver to remove the screw from the bottom of the front black case.
Use 00 Phillips head screwdriver to remove the screws from the top case (6 in all).
Remove the front case from the camera.
Use a 00 Phillips head screwdriver to remove the screws from either side of the communication board.
Desolder the wires and remove them from the communication board.