This one was a strange one, and worth sharing I think.

There were two kinds of 200g/m2 paper. The one worked that worked fine seemed to have a smoother finish. The problem paper seemed rougher. I did weight out samples, and they were both 200g/m2 (well within machine specs). Ok, ... it didn't help that the enduser was running it at plain media type. I thought: "This will be easy. Select Thick1 or Thick2 media type and be done." Not quite.

It was primarily the second side that presented with the problem, and the more consecutive prints the worse it got, almost to blank. I had a pretty good idea that it was second transfer since the untransferred toner would cycle it's way around the primary belt and overlay onto later prints. Our color specialist recommended cleaning the facing roller and using conductive grease at the contacts. The roller was dirty enough, but cleaning didn't help, neither did the conductive grease or the 2nd transfer roller. He also pointed out bulletin Color 089.

Bulletin 089 covers it perfectly. The first part is about cleaning the facing roller. The second is about changing 2nd transfer settings (05-2934 and 05-2935). According to the bulletin default should be 5. The preferred setting is 3 to address the issue, and there are sims for each media type, and first and second side, so you can set each individually. The 3 setting for both the first and second side was major improvement. The 1 setting was perfect. And I changed it for all the thick media types. Here's a sample:

200 gsm media.JPG

=^..^=