It was charging too slow. Why does not it charge anymore?

Hello,

I'd this 1st gen 3G IPad. It was normal until the last month. It suddenly began too slow charging - 20-30%/overnight. I have changed cable, wall adapter. They did not work. Then found this website problem might be caused dock connector or battery.

I opened the case and removed dock connector & logic board. Then I connected a controlled external power supply to batteries in order to charge them externally. I did charge them till morning. And left them for another day in order to ensure if batteries were dead. Batteries are fine. I serached and found dock connector, then replaced it. Result was same; too slow charging.

Now it does not charge anymore. I connect the cable, I see battery icon w/ red. But it does not turn into green and I get 'doesn't charge' message near the battery icon.

But if I leave unit connected to charge, a few hours later I see charge percentage has been increased 1-2%

-Do I need any calibration for battery after this dock conn. replacement?

-Do I have to re-install sw system? (Did anyone solve in that way?)

-Is the only way to replace logic board? (Did anyone solve in that way?)

Thank you in advance.

Kindly,

Taner