Mobile Phone water damage repair guide
It happens to the best of us; we drop our phone in the sink, toilet, a drink, or forget it's in our pocket when we go swimming.
Contrary to popular belief, if you take the right steps, the phone will be perfectly recoverable. The key thing to remember is it's not the liquid itself that usually does the damage, it's the current flowing on the PCB whilst it's wet, shorting components out and causing green corrosion on the PCB.
If you do get your phone wet, the first thing you should do is take the battery out! (As soon as you realise what you've done) Then, if possible, take the phone apart and put the PCB in an ultrasonic cleaner as pictured. If one is not available, then clean the PCB with methylated spirits and allow to dry for a couple of hours before re-assembly.
If you can't take your phone apart, then the only thing you can do, is remove the battery, leave in an airing cupboard or similar overnight and try it the next day. You might be lucky, you might not.