Make sure the ReadySet is properly connected to the solar panel or Grid/Mains charger (see pages 8-17 of the User Manual).
For solar, make sure the solar panel is placed in direct sunlight, without shadows or clouds. If the sun is low in the sky, or the day is cloudy or hazy, there may not be enough sunlight to charge the ReadySet. If so, you will need to wait for a sunny day. If it still does not charge during a sunny day, try using the Grid/ Mains charger.
For the Grid/Mains charger, first make sure that grid power is on, then plug the charger into a wall socket.