The flap must remain closed when the cable is reinserted during reassembly. Carefully line up the cable with the gold contacts facing down, and gently slide it into the connector.

OK, when I read those directions, I did it wrong. I followed the instructions and kept the flap closed when the cable was reinserted during reassembly. Of course I got a blank screen. It should read the flap must be closed AFTER the cable is reinserted during reassembly.

this is a great tip Steve!