Ive dropped my phone in water, everything works but the on/off button

redbubba02 besides the great answer by @j0vian I suggest that first you do not turn on your phone, charge it or try to connect it in any way. Remove the battery from the phone to minimize further damage. After that completely disassemble your phone by using these guides. Using 90%+ isopropyl alcohol, clean your phone by following this guide. It was written for an iPhone but all the points still apply to your phone as well. While cleaning, check for obvious missing or damaged components. you can always post some images of your boards etc. with your question so we can see what you see. Use this guide iFixitでの質問に画像を追加する方法 for that. Once it is properly cleaned, replace the battery and reassemble your phone. Only after it has been fully cleaned can you properly troubleshoot. Liquid damage is the hardest to troubleshoot and the most difficult to repair since virtually any part/ component may be involved. Your could simply be a shortened power button but it could as well be a failed component on the power circuit.