Samsung Xpress C1810W makes clunking noise and throws error #A1-4111

My five-year-old Samsung printer now makes a clunking noise when we try to print. The machine stops and displays error code A1-4111

The printcopy.info website lists this error to mean:

Description: Error #A1-4111 Call for service

Causes: The transfer roller can’t move the engage/disengage position.

Remedy:

1) Turn the machine off then on. If the error persists, turn the machine off again.

2) Remove the right cover.

3) Check if the connection between main board and Feed drive unit are correct.

4) If the connection is OK, replace the step motor of the Feed drive unit.

5) If the problem persists, replace the main board.

Notes:

I’ve removed small right cover and the connections seem correct (from what I can tell.)

We recently replaced all the color toner with HP-brand toner.

We’re clueless about our next steps.