My Yocan UNI only lights up when it is plugged in. The charging lights blink when plugged in, but when it is unplugged the light doesn’t turn on when I press the button. Also, it doesn’t seem to be heating up. Is there a way to fix this?

I have a Yocan UNI that lights up when I plug it in but doesn’t light up at all when it’s unplugged. Nothing happens when I press the button. Is there any way to fix this?