Screen dimming and sometimes go black after spill of tea

[wusikaka]

I have a macbook pro mid 2012 that have been spilled tea on. I have tried to clean the logic board. The screen works but keeps dimming and sometimes go black. Anyone know what can be the problem? I have attached a picture of the logic board and a picture of the screen when i boot up the computer. I believe that there is a problem with the backlight cause even when the screen goes black i can see what it shows if i light it up with a lamp. The screen can work as normal sometimes up to 30 minutes.