I have cracked the screen and ended up buying a new screen online (not through Lenovo) and replacing it myself. Now I am having trouble with the screen brightness keys. If I hold Fn and press the up key, the brightness jumps to the highest setting. If I hold Fn and press the down key, the brightness jumps to a much lower setting; there is no in between. The screen will only toggle between two settings: really bright or really dim. The volume keys still work just fine. Is it because the new screen is not whitelisted or?