A:Answer First did you fully charge the unit, not just a few (1-3) hours? A full charge usually takes a 12+ hours in the beginning for any power supply unit. It usually takes about a few charges to reach it's full strength. Next, check and see if your USB cable is working? Many times the fault is in the cable itself being worn on the metal connector ends. I have even seen new USB cables being defect. Try using a different cable. If All of these fail then may I suggest taking it back to the store for a new unit. There is a chance that it maybe defective or it died. Hopefully this will help you? God bless, tork49.