√ Problem solved.
I resetted the NVM flash module which stores all the dc129 paper registrations for the printer and copy engine.
The problem was also that the printer printed so much offset on the printer roller which causes over time
to see these annoying grey borders.
Furthermore, I changed the drums which also helped a lot.
I got it now. I replaced the Fuser and now the strokes on left and right side of my SRA3 prints are
gone. Furthermore, I bought a new drum R1 for black. Grey and black gradients for color matching are much
better now since I replaced it and made a color calibration on my Workcentre 7535.
thanks for the advise. I got the machine used from someone working at a Xerox certified support and reseller
company and I thought. They must be knowing what they are doing. The vendor said, they entirely "cleaned"
the machine before selling it.
I made approx. 1000 prints maybe since I got the printer. Quite a lot of toner though for 1000 prints.
I think it's the Fuser unit. Whenever I remove and re-install the Fuser unit, the streaks on left
and right on SRA3 prints change slightly. I think it's the Fuser.
The black drum unit R1 was just like new. 99%. I got grey shades from top to bottom in the middle of the page.
I changed the drum R1 with R4 to see what happens.
Result: The grey shades 2-3% in the middle of my prints are gone. The grey streaks left and right are still there.
I bought a new 100% original Xerox drum unit which hopefully arrives this week.
The prints on gloss paper now show yellowish 2-3% shades. I hope to get rid of them after installing
the new drum unit for R4. However, I don't think the grey streaks problem on left and right on SRA3 prints
will be gone. I doubt very much. A new Second Bias Transfer Roll is already installed.
Ok, it is not from fuser and I don't know the diferences between original and non-original fusers (I never saw non-Xerox fuser).
So, it could be from used drum cartridges, from the Transfer Belt or from the Transfer Belt Cleaner.
I did today after letting cooling down the Fuser for 40 minutes. I could see some black streaks on the left side of the red roll. Hm, I guess that's not a good sign?
The Fuser is as new 99%. Maybe it's an OEM product? Is there a difference in hardware between the
original Xerox and the OEM products?
Take out the fuser and make a picture of fuser roll (the red one), please!
I did that before. I attached the photos. I published and then the photos were removed.
Let's try it again. As usual in web development.
It looks like to be from fuser. Can you upload a picture with the fuser roll?
Also try to swap the drum cartridges between them to see if the issue moves to other color.