iPhone 4 got wet, but works, screen dark
Iphone 4 was dropped in water. Did the bowl of rice, no joy.
Disassembled iPhone, cleaned corrosion from mother board, various connection points (there was some significant blooms of greenish corrosion in a few places.)
Reassembled iPhone does everything - - EXCEPT - - the screen is dark. It's receiving texts, it can answer calls, I can unlock the screen and hit the home button twice and then play a song (these are the operations I could hit in the dark.) When plugged into my Mac, it shows up normally in iTunes. I did a restore, a system upgrade to the current iOS 5.1. Everything is fine, except the screen is dark.
How can I tell if the problem is the LCD/display assembly? Could the problem be upstream of the display (motherboard? cabling? or...?)? I would like to be able to find out what I can before spending money on parts which I may not need.
Any sage advice would be greatly appreciated!!