Chosen Solution
My sisters iphone got damaged while she was cooking by steam and has the same damage traits as being dropped in water. The 2 white dots inside the phone that indicate how much water has got in havent been effected. I opened it and and cleaned the connectors but nothing changed, the phone’s backlight doesn’t work anymore and the touchscreen did work for a while but it seems to have stopped working as well. I cant see any corrosion or visable damage besides some possible water stuck inside the glass. The only other thing i can see is the small connector the number 3 connector has a black spot on it so im not sure if that could be anything
If the LSI indicators show no liquid damage I would take it back to Apple for a warranty repair.
danny, since you already mentioned it, same traits as water damage, treat it as such. Follow this guide to get you started. It is for the 3G but essentially the same procedure. Hope this will at least get you started. Good Luck.