To add to what wayout said, the factory settings restored message comes from a failure in the battery circuit.
If the batteries are dead or the holder is corroded and the current isn’t passing then you will get that message everytime you turn the machine on.
If the holder is clean and you are confident that the circuits are being made start with new batteries. If that isn’t working then a dmm will help you see if you are getting voltage beyond the batteries to the board.
Dave