I am having a similar problem.
I just bought a samsung galaxy tablet last month. Last weekend, I connected it to my computer. Everything worked out well. Now, a few days later, it will not charge, register a charge, or show it is connected to the computer. I am using the cord and outlet plug in that came with it. I have a 64 GB card in it because I was transferring music to my tablet. I didn't drop it. It didn't get wet. There is no red X on the battery. It is at 40% right now. I haven't tried charging it since I connected it to the computer until last night. When I go to battery settings it says that the battery is discharging. I rebooted it. I turned it off and on many times. I restarted it. I took the memory card out and in many times (and I did safely remove it) I plugged other devices into the cord and they worked. The outlet on the tablet is not bent at all. I turned it off an 4 hours ago to see if that would help. I just turned it on and the same is still happening. Please help!