With unplugged charger, no signs of life.
With the charger connected, there is a battery LED that flashes and if I press the power button, nothing happens. The LED of the shift key lights up when the power button is pressed, when the button is released the LED goes out.
https://drive.google.com/open?id=1IhBfSMqV5e5wUBoCDVgVFpKCef4NLKVv