WFD won't stay on

I just bought a SanDisk 64G WFD. I charged it full andpressed the button to start it but the blue light only stays on for a minute. Once in a while I get 2 minutes. What is wrong?

How long did you charge it? full charge take 3 hours and the amber light should turn off when fully charged? when it turns off are you doing anything? Do the lights blink in any unusual way? If not and it is fully charged and it keeps turning off then it may have a battery and would need to be replaced. 

I charged it until the amber light went off. It seems to turn off any time even whild charging. I did not notice any lights blinking in a unusual way. Thanks

how long is it on before it turns off? What are you doing when it shuts off?