How to repair water dameged phone of xperia z1

anoopteegalwar, you should treat it like any other water damaged device. First thing to do is to clean it properly. Disassemble it by using this video Clean it properly using this guide. It was written for a 3G but all the points still apply to your phone as well. while cleaning your phone, look for any obviously broken, missing or otherwise damaged components. Once it is properly cleaned '''replace the battery" reassemble and re-evaluate. With a new battery and properly cleaned, you will have a good starting point should any further trouble shooting be necessary. If you do not do this, you will continue to have corrosion damage Remember that water damage is the hardest to diagnose because any part may have failed.