If its shot, you wouldnt have to replace an entire computer, just the power adapter. If saliva got past the LED onto the sense board inside the connector, it may still charge your laptop, but report incorrectly. You shoudl see an indicator on your laptop when the cord is attached, if you see this indication then the laptop is taking a charge. If no indication, then its time for a new power supply. If you have to replace it, buying a used one off of ebay or one of those universal power supplies with the different cord attachments might be cheaper than buying directly through $$$APPLE$$$