Backlight flickers after water damage

I received a MacBook Air 2012 with water damage and somehow I managed to get it back up and running after cleaning all the contacts with contactcleaner. the only problem that stubbornly stays is that the backlight of the LCD flickers or sometimes the screen just turns off. removing the connector and using an external screen results in a working MacBook Air without problems. But of course that sort of beats the purpose of having a laptop. 

I know you'll say, just get a new logic board, but I want to see if I can figure it out with the current one. 

Does anybody know which parts actually send the backlight signal to the LCD and if these things can be remedied? 

here's a video of how it looks like

https://www.dropbox.com/s/4z3ahyrwcl5uzi...