Really bad on first print out then gets better,
We have pulled the machine to workshop for investigating and are getting the same issue here
This is on a virtually new machine so far we have changed...
Primary Transfer Belt
Secondary Transfer Roller
We are in the process of changing the LSU as i type (will update)
The marks align perfectly with ID sensors , it looks like the transfer belt is not cleaning the id patches off .
Very Strange one this and this is a first for us so hoping some of you guys have experienced this .
You're doing way too much work. Check the two springs that make connection with the two points on the primary belt. These charge the metal roller inside the primary cleaning unit to pull the toner off the belt. I'm guessing you're also getting error codes like C7620. I had an M6525cidn that was doing the same thing. The spring was evidently missing from the factory. IMG_3440.JPGIMG_3442.JPG
Glad that fixed it for you. It took me a little bit of looking at the M6525cidn to figure out exactly how it worked & what it was trying to accomplish.
We're coming to London this summer for vacation, you can buy me a drink.