Nokia Power Keyboard not responding to Nokia Lumia 2520

My Nokia Lumia 2520 tablet is 9 months old, and the Power Keyboard is months old. I have been using the keyboard sporadically, that is, maybe once or twice a week. Recently I cannot seem to be able to use them together. When I plug the keyboard to the table, everything stops responding. The keyboard does not work, the tablet does not work and the screen goes black. What is happening?
