Hi,
It can be the LED units dirty. Use the cleaning rod's to clean them.
Or it could be the fuser roll used.
It will be better if you can upload some images with issue.
Gabi
WC 7545 - I am getting white lines in full black prints (or partial). It is obviously where toner is not adhering. I have troubleshot it and it is only in black, not the colors so it has something to do with black hardware/rollers. I have exchanged/replaced IU's, and still does it. I had this issue in the past and a certain roller was replaced for black but I cannot remember what it was.
Does anyone know what roller that may be? It is specific to the black only.
Thanks in advance