When printing, there is a thin black line along the edge of the sheet, what should I do?

Question

Seal

Greetings!
We have a kyocera 4020 in our office.
When printing, there is a thin black stripe along the edge of the sheet, although the MK kit was changed in it quite recently.
I am attaching a screenshot of what it looks like:

What could be the cause of this print defect?

Answer 1

Something is wrong with the printer. To service.

Answer 2

Most likely you have toner wear on the Teflon roller (in the worst case, a defect). In most cases it is sufficient to clean the Teflon roller. If carotoron is present in the design, then it is also worth checking.
About the photo-drum garbage froze, it is better not to touch it under any circumstances. If the squeegee that cleans the photoconductor has deteriorated, then it is better to replace the entire part.