I have a casio SF-R20 diary,it was working properly .It remained idle for a long time,now i have changed the b?

I have a casio SF-R20 diary,it was working properly .It remained idle for a long time,now i have changed the battereis but its screen is showing black check with all titles on the left pannel and not responding to the commands,what i have to do now? thanks. Try the suggestions below or type a new query above.