Success Thank you so much for your help Porty

I made the key and did as you suggested. There were no beeps but the constant beep has stopped. The screen now reads 'Head up'

Thanks Porty I will do that today. I cant see any batteries anywhere though !

I have a Sharp UP-700 which has been in storage for two years. All was well when it was put away but now when it is switched on there is a constant beep and the screen message reads Start code 00 Cha...