Chosen Solution
So, I dropped my phone in water many times. One week I it turned off and kept trying to turn on but can’t. I tried charging it for 2 days but it didn’t fix it. Please help.
BEFORE DOING THIS DISCONNECT THE BATTERY AND MAKE SURE THERE IS NO CHARGE GOING THROUGH AT ALL! Purchase some isopropyl or ethyl rubbing alcohol (ethyl will keep streaks off metal and glass). Take apart the iPhone completely and make sure the screen is separated from everything else. Grab a bucket and literally bathe each component in rubbing alcohol. Don’t be afraid to pour alcohol directly onto components (except for the screen and battery) or submerge them entirely. Scrub each component with a spare toothbrush thoroughly. Once finished, let each peace dry for at least 24hours, but I recommend waiting 48 just to be safe. Re assemble it and see if it powers on. I’ve had this work on a multitude of computers and a Nintendo 3DS at my shop. Just remember to disconnect the battery, and to let parts dry completely. If they are not 100% dry, it will cause problems. It helps to dry them if you have an air gun that you can blow the components with.