After years dead, MacBook display suddenly worked, until PRAM zapped
Well speaking of "arcane",and "those kind of guys" are still around, for clarity see the answer below :) 

So what you need to do is open it, remove battery, and clean the mother board and plugs ect.... using NON metallic cleaning objects like toothbrush and q-tip. 

Use alcohol (for grease) and Vinegar(or pure lemon juice without sugar) for calk deposits from your spill. 

The density of interconnects is very high and even a small amount of semi-conductive dirt can do what you are experiencing, so give it a good scrub.

Good luck :)