http://support.apple.com/kb/HT3425?viewlocale=en_US
The rules are clear for them. If these sensors indicate that a liquid came into contact with the machine, the guarantee, legal or extended by Apple care, will be regarded as cancelled. The note leaves an open door however since only the problems involved with the immersion will not be covered. It will be necessary however to discuss with the "after sales service" to know if the breakdown is related to a liquid or another cause. Indeed, with the sensors being placed under the keyboard, there remains the possiblity that a little liquid has just "coloured' them without reaching the mother card, that could breakdown some time later on.
