DC 250 fading on images

[savedsoul]

I have a 3 year old DC 250. It has a fading section running lengthwise on the printed paper. It appears clearly on a 20% screen of cyan printout, 20% magenta printout and 20% yellow printout but not on a 20% black printout. I have cleaned the ROS glass for all the colors, interchanged the BTR assy and Belt and even the developers and drum housings but no change. (I have another machine that I just used to interchange these parts). What else could it be?

[tech_c3]

try to clean the ROS window.

[savedsoul]

Done that. Interesting thing is that the faded strip is on the three colors c,m and y. A black screen printout doenst have the strip and its at exactly the same spot on the three colors.

[Milo Wilson]

Did you happen to leave the drum assys out in direct light for more than 2 min? Sounds like a light "burn" on the drums. Somehow the black might have recovered or luckily not affected for whatever reason.

[savedsoul]

I interchanged the whole drum and developer unit tray with the one from my workcenter 7665 and the problem still persists.

[xcopytech]

did you tried to remove ROS and clean it.

[kalindd]

A scan of the print will help a lot.
Can you post one?
Otherwise everyone is guessing from long distance

[TechMate]

I have a 3 year old DC 250. It has a fading section running lengthwise on the printed paper. It appears clearly on a 20% screen of cyan printout, 20% magenta printout and 20% yellow printout but not on a 20% black printout. I have cleaned the ROS glass for all the colors, interchanged the BTR assy and Belt and even the developers and drum housings but no change. (I have another machine that I just used to interchange these parts). What else could it be?

Remove the ROS assembly and clean it (not just the ROS window). You also need to change parts you mentioned to a NEW one (not interchanged from a working machine) and scan a sample as suggested above. Let me know what the outcome is. thanks

[savedsoul]

a scan of the print issue

Attached is a scan of the image printed on a 20% cyan screen. The same strip occurs with yellow and magenta but not on black. No strip appears when I print any solid color. Hope this helps

[xcopytech]

remove ROS and clean it.

[kalindd]

Definitely ROS.
Take it out and clean it.
Pay close attention to small mirror located just after the yellow or cyan laser it is at 45degrees and is 1x1 cm. This small mirror is causing this line in cyan and yellow. I needed 1 whole day and like a hundred times cleaning to find that this small mirror is causing this line.
It does not make sense, the line on magenta, to be on the same spot but who knows. Clean the all ROS mirrors.
But this definitely looks like ROS problem.
Hope this helps.

[zulky_lan]

i think u problem is developer
have you try replace the developer assy
i suggest u replace developer and developer assy(with same time)


please inform me what the result

[savedsoul]

Sorry I took too long. I interchanged the 2 ROS boxes and the problem disappeared on the DC 250 but now its on the workcentre since thats where I put the offending ROS boxes. So its definitely the ROS. Thanks guys!

It still shows on the cyan and the magenta 20% screens. The strangest thing about this problem is that it appears on the exact point in both the cyan and the magenta and yet they use different ROS boxes. Anyone know how this can happen? There are soo many mirrors and lenses in there.

[XeroxTechBrazil]

Ros Contamination PPT Presentation

I have a 2008 Ros Contamination Seminar in PPT format that I can email anyone interested. This has a discussion of causes, fixes, w/ numerous photos and illustrations. One of the samples in the PPT is identical to the sample you posted.

Also, SearchLite has a couple of hits on this problem, one with a photo pointing out what needs to be cleaned.

Leave me a message or email me: JorgeXcalak@live.com