If your IPhone got wet
If your iphone got wet YOU HAVE TO TAKE IT APART.
Rice is a good start, but getting it apart is better.
Electricity and water dont like each other.
Corrosion starts almost right away, rice will help for a while but corrosion will take it toll eventually.
Here's somthing i send to people with wet iphones to help them try and repair them, themselves.
Heres what you need to do.
Completely disassemble the phone.
Remove the main board
Remove the metal covers and clean up the main board.
Use either an ultrasonic jewelry cleaner, or just a toothbrush and alcohol.
Use a magnifying glass to see where there is corrosion.
Pay attention to the LCD connector area, pins should be nice and shinny.
Check around the coil area, and the components next to it.
Like the 109b ic, its the small black square next to the coil.
Theres three solder points on both sides. The side closest to the outside gets corrosion between them and that can cause the backlight to not work.
Just because the water indicators are still white means nothing.
Look on the backside of the board too.
Water gets between the batters and the board, so clean the underside too.
Try cleaning it real good first. If no backlight, check the LCD.
Try your LCD assy. in another 3gs and vise versa. It could just be the LCD.
But clean the board no matter what.
If you need any other help contact me.
I sell the coils and the 109b ics if you need them.
tinner105@roadrunner.com