HP Color LaserJet CP3505 - Rollers

Question

We have an HP Color LaserJet CP3505 printer in our office, which has recently begun leaving magenta coloured marks at intervals up the centre of every page that it prints.
I checked the roller film and found that it had the marks also, so I wiped them with a dry, lint free cloth.  When we sent a test print, the marks still appeared on the page and had reappeared on the roller film.
It would seem that one of the rollers that grips and feeds the page has rather a lot of magenta toner on it.  How do I go about accessing and cleaning this roller?

Answer 1

I had the same problem with black streaks and following HP's cleaning instructions repeatedly did no good. I also found no useful advice anywhere on the HP site, though I did find this unanswered query. Investigating inside the printer, I found that the photo drum in the black cartridge had corresponding streaks. (You can see it when the front door is half-open or if you pull out the cartridge and cautiously push open the cover between its holding lugs.) I doubt that the drum can be cleaned but replacing the cartridge cured the problem competely. I think HP's user support is truly dismal. If questions like this one arise repeatedly (at least twice on the present evidence!) and are not answered by someone from the company, a forum like this is pretty useless. I am reminded of the ineffective telephone 'support' that failed to explain how to set up my w2207h monitor. I took it 20 miles back to the store where I bought it (prepared to reject it) but got an immediate answer there.