Vertical Repeating Black Lines when Printing - Xerox c70

[INTL Minute Press]

Anyone have an idea why we are getting repeating black line on all print outs, all colors. I've swapped the drums out several times (color and black) with different drums and we've also wipped down the ibt belt and these lines will not fade and seem to repeat like it was on a drum but the lines never change after swapping each drum and test printing. Attached is the image of the lines and suggestions??

[GabiE-Xerox]

Hi,

Measure the distance between marks please.

Gabi

[INTL Minute Press]

Thanks for your reply. It measures just under an inch & 1/2. Looks like 1  7/16.

[GabiE-Xerox]

Could be from black developer housing.

[INTL Minute Press]

Ok thanks, that sits directly next to the drum correct? Is there any methods to cleaning or vacuuming it off to try to fix issue or do you think it needs to be replaced? We don't have a service contract so I'm trying to figure it out so maybe I can fix this issue.

[INTL Minute Press]

So I removed the black drum and spon the developer unit and seems to be fine, hard to tell with all the developer stuff on it. The weird thing is I put in another (used) black drum from the shelf and some how the marks are now at the top of the sheet but the exact same distance as before....???