ALL WATER DAMAGE

First you need to do is remove your phones battery memory card sim every thing. Then dissemble it.
Then wash it when a cleaning liquid like Isopropyl carbon tetra chloride(CTC) or WD-40 or any other cleaning fluid you may have.
Heat it up really well and make it dry with heat gun you can use Hair dresser.
Check or change and remove 1> charging (USB) connector, 2> capacitor, 3> Battery line circuit, 4> IC More in if u want to check the shoting cause.