Hi everyone,
I too had the issue with project 11 (crystal ball) where the LCD would be powered on but nothing would show (except for the top row of pixels when the pot was turned all the way clockwise). In my case, the source of the problem was some extra solder between the pins that short-circuited the screen. I scratched it gently with a pocket knife and the LCD started working as expected.
So, if your LCD powers on but doesn't display the right messages and your code and breadboard layout are as shown in the book, check to see if the LCD pins are properly soldered by the manufacturer.
I hope this helps!
