its probably a failing psu. you burnt something out in the psu and now its unable to maintain power to the computer. If the case is closed, not much water is going to get in there, but it will get in through the rear of the psu. unless you have a fan or something on top the water could have gotten into. If anyone ever spills something on the comp, it should be take apart completely and dried out for a full day, not just an hour.