Not the toner. Developer housing is a module who transfer toner to imaging unit. You will need a tech for this repair.
Are you saying by using the original xerox toner will improve the quality?
Yes. You must replace the developer housing and developer material.
Just swapped magenta to black, and it looks like that imaging unit does have problem, see below. I will order one this afternoon.
However, the black steps print does look smudges. Any hints?
Swap the imaging unit with yellow (let say) to see if the issue move to yellow. And if it is so, you must replace that unit.
Here is my black color imaging unit, before and after cleaning.
I can still see a track on it after cleaning.
I have tried to print several blank pages, and clean the imaging units, but the problem still.
Please see the below on both pages. Please let me know what else I should look for.
Thanks in advanced.