The same happened to me. While unplugging the cable I have broken the lock. I realized it only when putting everything back in place. After several attempts I noticed that if I pressed with a finger where the lock was the LCD worked.
So, I inserted the cable and taped it so that it doesn’t slip out. In the iOpener kit you get some transparent plastic cards (not sure what are they meant for). I cut 2 small pieces the size of the connection and taped them down firmly.
put everything back in and it worked.
The lock is there just to make pressure on the connection.