Dropped my phone in water, screen flickering, what do I do?

Alex Trevino, here is my answer to a similar question. "Rice does not work. IOt will not prevent corrosion! The very first thing you want to do is to stop using your phone. Stop right now and do not continue to charge or sync it. The very next step I would do is to disassemble it by following this guide. Take a careful and close look at all components and connectors. Truly assess the damage. Look for major corrosion, evaluate the pins in the connectors etc,. Take a look at all connectors as well as cable ends. After that I would suggest that you clean it a couple of times in sterile water, not drinking water. Use a soft brush and clean it very, very thouroughly with the sterile water. Depending on the amount of corrosion, you may have to remove all the EMI shields. Once you got the gross contamination cleaned, use 90%+ isopropyl alcohol and clean your parts some more. For a proper cleaning, use this guide. It was written for a 3G but it is still pertinent to your phone as well. I can not stress the importance of a good cleaning enough, so do it over and over while replacing the alcohol after each cleaning. Do not use compressed air for the cleaning since that can drive liquid as well as corrosion particles into areas that will cause trouble later on. Do not use drinking water, if you need to use water, use sterile water. Also, you do not need to leave it to dry for a day. Isopropyl alcohol in the higher concentration will evaporate quickly and dissipate the water. The importance here is the cleaning. Do not forget to replace the battery. This is a must and not an option. It will fail if you do not take care of it now. Also, I suggest to replace the lightning connector. The guide for that is here Yes, do replace the battery for sure. Use this guide for that. Keep in mind that water damage is the hardest to troubleshoot and to repair. the issue with your screen could be the LCD itself or the backlight circuitry on your logic board. Hope this helps, good luck.

Dissassembling it will invalidate any warranties you have.