I had this problem for months with two tablets I purchased for my grand daughter (first one stopped working so I bought another which promptly stopped working also. While power was flowing to the AC adapter the units wouldn’t charge. Decided to use the USB port with a 3.0 adapter and voila, I got one fully charged and running (for now, at least). Moving to the other one next. If problem persists I’ll make a claim in the insurance I bought when I purchased the second one. Hope this helps.