Iphone 3GS stopped working after falling in water
20 - 30 minutos
My mother's iPhone 3GS fell into water, and we were quick to do just what everyone over the internet did: turn it off and leave it several days to dry (we put it in a bag with rice). After this the iPhone did not turn on again. Changing the battery solved the problem!!
The repair process was pretty simple - thanks to the guide here on ifixit, of course. I actually forgot to buy the suction cup, so I inserted a thin razor in the bottom part of the iPhone to bring the display up.
If your iPhone fell into water, dry it and hope for the best. If it does not turn back on and you are not sure what the problem is, consider trying a battery replacement. It's the cheapest essential part of the iPhone, and it's worth the shot. You might just bring your iPhone back to life.