1. The best way to kill a wet phone is to dry it. All the water evaporates, concentrating all the impurities that were in the water (they don't evaporate, only the H2O does). And, if you dropped it into the ocean or - even worse - a chlorinated swimming pool, evaporating the water leaves concentrated acids (the pool has chlorine - water and chlorine combine to form HCl - hydrochloric acid). You want to
flood the phone, no
drown the phone, in alcohol. The plain stuff you get at the pharmacy. (It's not water, it dilutes the impurities, washes them out, absorbs the water - and leaves nothing.) See
Oh, no! My Phone got Wet!
2. The digitizer is the outermost layer of glass on the screen. The screen is LCD, so there's a digitizer, an LCD layer and an LED layer under that, to provide light to the LCD. The LED layer isn't turning on. Why? The LED layer could have gone bad, but I suspect it's whatever is driving the LED layer. So you're probably in for a new motherboard. Shop around at repair shops that friends and neighbors recommend, and see what they estimate the repair cost to be.
THIS IS NOT A DIY PROJECT! If you try, it's almost guaranteed that you'll be back here saying that you replaced the motherboard (because it was
so much cheaperthan any shop wanted, but now you can't even see anything on the screen if you shine a light on it. And at that point, no reputable shop will repair it.
@
Galactic Zoo, you can if you've been doing it for years, and the problem is a simple one, like this one.