When it comes to water damaged devices. It gets tricky. Most of the time its a 50-50 chance to get the device to power on again. Most of the time you need to do some soldering touch ups under a high power microscope. Also, use 90%+ alcohol to clean up any corrosion. If you can, check the voltage on the battery with a DMM should be about 3.5-4 volts. Unfortunately, if you can't get the device to power on you can't get data off. :(