My phone has been dropped into water and it is not starting

@atharvagupta you want to treat it like you treat any other water damaged device.

For now, stop continuing to try to charge, sync or otherwise use your phone. This potentially can make a bad situation worse.This may further damage your phone.

The next thing to do is to clean it. Disassemble your phone using these guides. You must remove all EMI shields from the circuit boards. This is for the main board as well as the daughter board (Sub PBA). If you do not remove those, you might as well not do anything. After you removed those, clean the whole boards, connectors and all with +90% (minimum %)isopropyl alcohol. Follow this guide, and even so it was written for an Apple iPhone 3G, all the points are still pertinent to your phone as well. While you clean your boards, check for any obvious damage, like burned or missing components etc. When it is properly cleaned, replace the battery. All these steps are to avoid delayed failure caused by corrosion. Best thing to do, would be to clean it with an ultrasonic cleaner, but if you do not have access to one, this will at least help. Once all this is done, reassemble your phone and reevaluate. Until it is cleaned, everything will only be a guess. It is possible that you have a bad charging board or a bad component(s) on the power circuitry etc. WE can check all of that once you have everything cleaned. Even with all this, water damage has only a small chance to be fully repaired, but at least you can give it a try.

Before you check the components listed in the Samsung Flowchart, you must clean your boards first.

Component Layout

While you work on your phone, take lots of pictures. Once you are done with it, take those pictures and create a guide for iFixit. That will help the next person that has the same problem as you do. It's easy and fun to create these guides. https://ifixit.com/Guide/new The iFixit community will appreciate this.