NOTE: I do NOT speak for or represent Amazon in any fashion. This is a customer to customer forum.
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Try plugging it into a USB port on a computer for at least a few hours (overnight would be good). After that, unplug it and hold the power button in for exactly 30 seconds (time it). That process can sometimes wake a seemingly-dead device.
If that doesn't help, contact customer support. If it's less than a year old, it should still be under warranty. From any Amazon page, go to Help > Need more help? > Contact Us.