Take the battery out.
Put the laptop in a place where warm air can circulate, a warm cupboard or airing cupboard.
Leave it there for up to two days if you can.
To let any water drops evaporate, that may be causing a short.
Time and patients here are the key, with warm air.
To be honest it`s the first thing you should do when water is split on a laptop. you should never try to use it after, but instead follow the trick above to cause more damage by water still sitting on the circuit board.
Give it a good dry out by putting it in a warm air environment.