A full cup of coffee (yes about 1.5 cup) was spilled on a few months old mac air mid 2011. The computer was still running when it was turned off, but did not wake up again. After an expensive visit at mac service they foretold that all part were to be replaced and the repair price would exceed a new air.
First, everything was disassembled and all coffee residues carefully cleaned with a cotton swab. However, this didn’t do the trick so in a last desperate attempt all parts (except the display) was rinsed in distilled water until visual coffee was left and then placed in distilled waster for a few ours. Dried all parts for 24 h (dry atmosphere). When the computer was put together again it just started!
Everything worked just fine but the keyboard. And it couldn’t be fixed with the waster method. The new uppercase bought from ifixit did the trick. And I’m writing this on the air now…
Don’t be afraid of trying it your self, I was at first but it is really simple following the guides on this webpage.
If you don’t want to buy a pentalob screwdriver required to open up the air, modify a normal scremdriver and it will fit really well.