How do I fix and E0 error on my Samsung ER-350?

This Samsung ER-350 electronic cash register was used only 3 months then stored for 4 years before plugging it in again. So, all programming was gone and everytime I try to do anything such as program a date is beeps and displays "E0".

I have tried the clearing process of holding the "Clear" button while plugging in and the unit does not print the "Initial RAM all Clear" message like the manual says it should.

I have also printed Z, PZ and Time Period reports thinking that would clear out something. They are printing out very strange with weird characters. Also, at one point, it looked like the date printed out August 2024 if that's any clue.