DC242 Image Quality - advice please :)

[steveclv]

As you can see from the test print (A4 LEF from Tray3) I am getting both horizontal and vertical defects and ONLY on the Black (B/W) mode - the 3 colors are all perfect.

I changed the Black drum and it made no difference so not drum related.

Any ideas please

Thanks

Stevexerox.jpg

[Jake2o]

I'd be looking at ROS unit and Dev housing in that case.

[Scse]

The process direction deletion towards to top is either a clump in the developer housing, or crap on the K ROS window. Developer clumps are easier to diagnose.
Remove the developer hsg cover and spin the dev roll by hand, if you see a bare spot, youll need to remove the toner clump stuck behind the trim bar. Spin the developer roll by hand to make sure the clump was removed.

What's the spacing on the vertical banding? If its 18-36mm, you need a new developer housing, a ROS would have very narrow bands, around 2-3mm spacing.
Start with a new K developer hsg, ROS is a pain to replace and just cleaning the ROS window or polygon mirror fixes majority of ROS IQ issues.