I've been experiencing this yesterday while charging my tablet in my living and bedroom and it didn't work it just got off for a little while when it was working a little bit. But now it won't work. On my tablet!
Your adapter is 5 Volts, 2 Amps, you should have a reading of 5-->5.2 V, current of 1.5-->1.7 Amp. Any thing under these readings, you are having bad adapter or bad USB cable. or bad USB charging port, or bad battery connector, or bad battery. You can only find the source of problem by eliminating one by one.