My iPad 2 charged perfectly for 2 months, then started only charging at full charge speed intermittently but would still slowly charge (no charging indicator), and now is not charging at all. During the period of charging problems it has only been recognized once by my Macbook, and now not at all. I am using the supplied charger, the supplied cable, and have also tried various other cables including a Griffin cable and car charger meant for the iPad.
I have looked at my old iPad 1 internal dock connector (I never had charging problems with my iPad 1) and it is silver in appearance and I can see the "teeth" clearly. My iPad 2 internal dock connector is black and I cannot see the teeth.
I don't know if that can be the problem.