Cut your losses. Put it on ebay. Even water damaged, it will sell, trust me. Get what you can for it and then, buy a new one.

 

About the distilled water comment, and your response. There probably isn't corrosion at all, what could be happening is that the water deposited something (maybe soap, minerals, etc.) very small onto the PCB and it could be shorting it. You can try distilled water but my favorite is Isopropyl Rubbing Alcohol, anything with >70% alcohol will work good. I use it on my computer a lot, because my Processor and Graphics Card are liquid cooled sometimes I spill a mix of water and anitfreeze onto the motherboard when changing the contents of the system. One time it was so bad that I just bought a ton of the rubbing alcohol and had to dunk my motherboard into a tupperware container filled with the stuff. What it does is absorb anything deposited there (whether it be minerals, soap, antifreeze etc.) and it evaporates extremely fast taking the deposits with it.

So basically you can try dunking your phone in some isopropyl rubbing alcohol for about minute (or the individual parts if it still taken apart, this would be more thorough too) and let them sit out in the sun or somewhere warm for a day.


Oh yeah, leave the battery out for this one. You can take a Q-tip, dip it in the rubbing alcohol and clean the battery contacts then let it dry with the rest of the stuff, that's all it should need.



EDIT: When the parts are in the rubbing alcohol bath don't forget to swish it around for a bit. Around 3/4 of the time that it's in there.

 

Youre hosed because even if you had insurance they dont cover water damage, and there is a way they can tell if it has ever been wet.