How to mend Samsung C520

My Samsung ER 650 screen is black?

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

samsung 4615 cash reg ?

change tax for er4940 samsung?

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

does not print full amount on till entry?

closed message? samsung er-4615?

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

Samsung er4615 closed?

samsung er150?

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

How can i clear extra lines appearing on screen?

Samsung ER-5100?

Cash Register?

Memory All Clear a Samsung ER-4615?

cash registers ER-4615?

fixing key issues on a samsung ER 5100?

how can i fix my Samsung ER290 cash register?

Samsung er290?

Samsung ER 4915 not working?

samsung er290 cash register?

How do I mend Samsung ER4615?

How do I clear an error code pp?

Battery?

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

I need to reset my Samsung Cash Register?

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

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

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

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