Hi,
I also encounter similar problems when I tried to perform the first charged, it was not successful till the battery drained out, tried to with other USB adaptor also doesn't seemed to work.
Later i discovered that the original adaptor(2pcs) was the source of the problem, they must be properly fitted an a "CLICKED" sound must be heard, if you could not hear the click sound and the wall plug with the 2pin unit, than it will not work. Make sure the 2pcs adaptor is tightly fitted.
My was TF201
Cheers