does this look like a ROS problem?

[dc260]

So finally have traced the problem - it is the k bias hvps turns out it is cracked.

[rafiqm]

So finally have traced the problem - it is the k bias hvps turns out it is cracked.

Good to hear that you solve your problem. Can you share the picture of culprit.

[yomba]

As I am the newest of noobs for Xerox I'll be interested in seeing what the actual solution for this is.
If I had seen the vertical voids in the black portion of a test pattern like that one (assuming that is process black from a mix of CYM toner, not standard black from black toner) on the machines I've actually worked on for a while, I'd take that as a color alignment problem and check the sensors that take care of that alignment first, and then do the service mode color alignments. But that's probably not even a little right here. I don't even recognize that test pattern after all.

How many clicks are on this machine? have you tried the mcu board?