Hi,
When you have a water damaged phone you must do this:
- Remove the battery and don't try to switch-on it.
- Disassemble the phone and dry off the water (stay it disassembled for some hours).
- It's good to clean it with an alcohol.
- If you have a magnifying glass, check the mother board and all connectors for oxide.
If this not help you, seek help from a mobile phone technician.
Regards.