How to mend Samsung Er-a450t

On screen is 'PCo' and nothing is functioning, how to correct?

fixing key issues on a samsung ER 5100?

how can i fix my Samsung ER290 cash register?

my samsung er-150 cash register makes a high pitched alarm sound on switch ?

does not print full amount on till entry?

Paper in my Samsung ER4915 jammed. Now it doesn't work at all?

I can't open the drawer. It has a squeal like a key is stuck?

How can i clear extra lines appearing on screen?

Samsung er290?

How do I clear an error code pp?

Memory All Clear a Samsung ER-4615?

Samsung er4615 closed?

cash registers ER-4615?

Battery?

clear E3 error code on samsung er-290 cash register?

How do I mend Samsung ER4615?

Samsung ER 4915 not working?

samsung er290 cash register?

samsung er150?

can non-upc codes function be disabled for samsung sps 520 register?

samsung 4615 cash reg ?

Samsung ER-5100?

I need to reset my Samsung Cash Register?

closed message? samsung er-4615?

Operator's Manual - Samsung ER-290 Electronic Cash Register?

Cash Register?

My Samsung ER 650 screen is black?

change tax for er4940 samsung?

Why does the error code E1 show on screen and high pitched?

How do I get the register key to turn to "P" for updating the sales tax?