Why black lines and shades are appearing when printing documents from the mf642dw printer?

[MohamedUmer]

Hello there,  

I am trying to print a document related to the office, I am facing an issue with black color printing documents, as the paper printed with shades and lines shown in the image below.

other color documents are printing fine only black is printing like this, even after i changed the toner, its the same,

please let me know what measures to be taken here to  

I even changed the black toner, but its

 

[shadowsports]

Greetings,

Since the black toner is not low, I would open the printer and inspect the paper paths for spilled toner. A small vacuum can be helpful here.  The fixing assembly could also be dirty.  You can clean using the printers LCD. 

From the printer's LCD..  
Menu> Adjustment/Maintenance> Maintenance> Clean Fixing Assembly> Check that the paper indicated in the screen is loaded, and then select OK> Start> One sheet with a cleaning pattern printed on it is ejected when cleaning is completed.

[Amaslaluno]

Hi, when I attempt to do that, I am getting a “could not perform cleaning” error message. Any idea what the problem could be? Thanks!

[mreg]

It could be the use of third party toner cartridges.

[shadowsports]

Greetings,

Third party toner is certainly possible.  There's also an auto cleaning setting that if enabled keeps you from running the maintenance service manually.