I have a apple 3g 8gb Iphone that recently got water damage. Thinking that the phone was dead I took it apart to try to see if anything was visibly wrong with the internal parts. Then i bought a new iphone 3g 8gb that worked perfectly so i then took the motherboard out of my old phone, and the motherboard out of my new phone and swapped them. The Motherboard in the water damaged phone worked perfectly in the new phone housing with all of the new components. Then i took the new motherboard out an put it in the water damaged phone, and when i went to turn it on the apple symbol turned on and then off after 30 seconds. It is obvious that both of the motherboards work fine but what could be the cause of the apple symbol just coming on the one phone that got water damage even know the motherboard inside is fine? And btw I replaced the dock connector in the water damaged phone thinking that was the problem, so that is brand new. I do not just want to buy a battery and more components if i don't need to (hints the dock connector) Thank you for any help anyone can provide..!