HP Color LaserJet M451dn - black marks/smudge on paper

[Hannzz]

Hello Guys:

I am have HP color laserjet printer M451DN and when we print it shows black smudge line at the edge of the paper. I tried self cleaning option few times but these are not going away. How can I clean them manually? Thanks for your help.

[davidzuts]

Since the marks only occur in the color black that would indicate an issue with the black toner cartridge. Open the toner draw and remove the black toner and turn it over. Odds are there will be a black band around the drum at the end where the marks are made. In any case 99% of the time the toner cartridge needs to be replaced so that is the first thing I would do.

[Hannzz]

Thanks i will check tomorrow.

[Hannzz]

Thanks for support, you were right it was the tonner issue. We replaced it and now the problem is gone.