It's almost certainly the mainboard that is fried, and at $500+ to replace, probably makes the system a write-off, since you have no way to know whether the CPU, RAM, etc., has been damaged.

I have seen motherboards go on ebay for around $200 fwiw

probably you need to open your laptop to spare parts and let it dry... you may use a hair dryer @ low heat to dry all the parts there. I spilled a big cup of water on it and the only thing that is broken is my mouse pad. I was lucky on that one. It took me 3 to 4 days to fix it. Some times it works sometimes it doesn't. Use a napkin to clean all the parts and mainboard.

here's the picture that I open up my whole laptop .
http://img.photobucket.com/albums/v244/tmlkhanh/laptopnaked1.jpg

I did let it dry for several days.  I took out the hard drive, battery, memory cards and let them dry out too.  I then opened it up and dried off everything I could.  After several days of letting it sit, I decided to give it a try and power it up.  The green lights in front come on, the fans come on and the hard drive begins to spin, but nothing on the monitor at all.

 

Thanks.. I will check that as well.