My ZT 180 arrived, it booted (with very low battery). Touch screen, and all worked, even connected to my wifi. Powered off to charge, came back and all lights seemed off. Now I notice that the red light blinks slowly and the adaptor makes a clicking noise, but it doesn't charge and hence won't boot. Is it the charger or the tablet do you think? What is the power spec on the charger? Mine says 9V 2000ma. Thanks.