If your Ember is not powering ON or responding, first try a reset.
Press the touch logo while placed on the charging coaster to see if it powers ON. If there is still no power, and your Ember has not been powered for some time, place your Ember Mug on the plugged in charging coaster for approximately 2 hours to see if the battery was empty.
If that still does not work, check your charging coaster (if one pins on the charging coaster seems to be uneven or recessed, please proceed with contacting us at support@ember.com).