It sounds like the battery wasn't replaced on-time. Your dealer should replace it for you every four or so years. You have probably lost all programming and will need to RAM clear it and start again using the programming tables in the book. The information is getting difficult to find now but one of the users has all of the manuals here:
http://the-checkout-tech.com/manuals/cashregisters/Samsung3.php
Registerman, September 2013
