Lock+volume down won’t work and stuck in boot loop

aaronselenica  right now we are going by the assumption that your water got water damaged. In that case, the very first thing you want to do is to not try to restart, sync or otherwise trying to use the phone. 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. If you do not remove those, you might as well not do anything. After you removed those, clean the whole board, connectors and all with +90% isopropyl alcohol. Follow this guide , and even so it was written for a 3G all the points are still pertinent to your phone. While you clean your board, 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. Even with all this, water damage has only a small chance to be fully repaired, but at least you can give it a try.