Chosen Solution
This has happened to me before when i had the wrong screw in a certain spot. its like the screw is pressing up into the LCD, but this time the screws are in the right place. If i press down on the screen with too much pressure my finger will cause the Lcd to fog up while the screen is on and remains foggy even when i restart the phone
Its probably a bad screen but also check your battery isnt swollen and pressing up against the screen :)
