My phone fall in water.

Hi!

If you dropped your phone in water disconnect the battery and tear the whole thing down, until you have access to the mother board. I think this guide will be helpful. Let everything dry out for some time, if there still is water inside the phone, otherwise get some rubbing alcohol and gently clean the motherboard with it and some Q-tips. When you're done, put everything back together, and see if it works.

Since we're dealing with water here, don't expect what I suggested to be the absolute way to fix this. Water generally shorts electric contacts, so the motherboard may be fried, but there is no way of telling if you don't attempt to take some steps into solving the problem.

Report back with an update.