Sham Kumar you are going to run into other problems with this phone. Sony no longer has any schematics for any of their phones, so a lot of guessing about components on the mainboard is going on.
For now, the only thing to do is to try and treat this just like any other water damaged phone. You have not told us if you even addressed the water damage. disassemble your phone, using [https://www.youtube.com/watch?v=auWVkG_V4PY|this video] will help. then you need to clean everything with 90%+ isopropyl alcohol and a soft brush. Use [guide|5825|this guide] to clean your phone. It was written for an iPhone but all the steps are pertinent to your phone as well. You must remove all the EMI shields form your board to clean it properly. While you are cleaning it, check for any obviously damaged or missing components. Once cleaned and checked, reassemble and see what you get.