after cleaning dust from Gameboy screen and assembling it back, cannot see anything on the display

[falloutboy]

my gameboy's screen had some serious dust and i ripped it apart to clean.i separated the screen from the logic board and removed the black tape and a piece of plastic(well a blue rubbe like thing) and found out it was corrupted.after that i assembled the gameboy & now the sound and everything is fine but i cant see anything.!! any help???

[Quasim]

This might be some problem with the contrast. What you can do is adjust the contrast knob from the side of the unit. You will be able to check screen brightness from here.