I believe you would have to replace the LCD, I've had this issue in the past and I believe that's what I did. There should not be an "LCD Switch" and as for the stripped screw, I would try using a flat heat. I use two methods of removal of stripped screws. I either solder something into the screw and then remove it or I Dremel a pattern and unscrew it with a flat head.
I'm not sure if this helps but good luck!