Hi
Dont trust Apple Genius. If I paid them to replace the LCD then I would had the same problem
I have replace the screen and inverter; had a spare data cable and it didn't work.
I'm trying to get hold of an inverter/antenna cable to see if was that.
Also when I press some part of the top left or right casing the screen goes back to normal
Gonna check the top casing to see if there a short too ;-)