Iphone 3G not charging? Hardware problem

[gsmsalers]

Hi.
I have Iphone 3G doesn't charge at all. So I replaced new battery. after I installed the battery the apple logo only came on for a few seconds and went out. I charged it for over a half hour and couldn't get the phone boot all the way up. I tried that battery on other Iphone it works fine. I already replaced usb charging port.
So what could be problem. I can see little bit water damage.
Thank you.

Hi.
I have another Iphone 3G which need activation. logic board bent nearby usb port connection.
Now it can charge, but pc doesn't detect any Iphone. I already replaced usb port. Now I know it is logic board fault. Is there any solution.
Thank you.