Dead MacBook

My mother-in-law just gave me her dead MacBook to look at. She says she spilled a cup of coffee on it. It worked for another 2 days and then just went dead. I just opened it up thinking I would have to put a new logic board in there, but there is no, I mean zero evidence of a coffee spill. No a single dried brown drop of coffee to be found. Suggestions?? Has anyone faced this before?? Help please.

Well, even if you can't see any evidence, obviously something bad happened.
Did you really get down to the logic board? Hit ifixit.com for really excellent instructions. I would put it in front of a fan for a full two days of dry out.
Seems the most common problem with water/coffee/beer is the battery. While it is drying out, find a friend who will let you test it out.

Yep. I totally disassembled since I was going to just replace the logic board. (Don't have the new one yet.) Computer is totally dried out. This happened a few weeks ago. I was expecting to see some corrosion from the acid in the coffee or at least some coffee spots. But nothing. Battery, as far as I can tell, is working. It has a full charge to it. Is it possible that the power switch itself is damaged?

Yes, it is pretty hard to diagnose water related problems. Some itty bitty wire can short out, water evaporates, no evidence of the crime. Good luck with this!