dc 242 white lines on all colours

Discussion in 'Xerox Color Laser Printers & Color Copiers' started by Chrisio1977, Mar 16, 2019.

  1. Chrisio1977

    Chrisio1977 Member

    Joined:
    Feb 2019
    Messages:
    10
    Location:
    Uk
    Hi.

    As you can see on the sample print I am getting white lines/deletions across all colours in exactly the same position and I am also getting a smearing effect on the transition between the solid colour and the lighter colour.

    I have managed to stop the machine with an unfused print and it shows the exact same image which should rule out the fuser. I have cleaned the cleaning blade and that looks OK.

    I think I can also rule out the drums/devs and ros units due to the defect appearing in all colours in exactly the same position.

    To me this leaves only the transfer belt or something actually scrapping the toner of the belt but I cant see any thing obvious.

    does anyone have any suggestions as to where I need to look or is it going to be the transfer belt (which I don't want to replace if I end up with the same problem.)

    Thanks
    Chris
     

    Attached Files:

  2. adriansto

    adriansto Senior Member

    Joined:
    Apr 2011
    Messages:
    136
    Location:
    somewhere in europe, near Black Sea
    Can be inlet guide of belt.
    Remove IBT assy and do a deep cleanning of it.
     
  3. Chrisio1977

    Chrisio1977 Member

    Joined:
    Feb 2019
    Messages:
    10
    Location:
    Uk
    Thanks very much - My tech is coming hopefully today and I will get them to do a full deep clean of the machine and see if that resolves it.
     
  4. OkiTech

    OkiTech Senior Member

    Joined:
    Jan 2008
    Messages:
    744
    Location:
    NEW JERSEY
    This much destinguished lines could be from debris stuck to a laser slit glass, blocking the laser beams. If you could take the drums out and look and/or if machine has a sliders-wands to clean them (many machines do, like xerox 7800 family printers) do the cleaning and see if thats bring any results.
     
  5. Chrisio1977

    Chrisio1977 Member

    Joined:
    Feb 2019
    Messages:
    10
    Location:
    Uk
    thanks. The tech has been out and been through everything - stopped the machine mid print and the image on the transfer belt had the deletions evident. Cleaned up everything possible he could see - laser glasses all clean etc - its almost as if something is hanging down and stroking the image on the transfer belt. Nothing worked. Out of desperation we are changing the transfer belt although both of us are not 100% that is the correct course of action.
     
  6. OkiTech

    OkiTech Senior Member

    Joined:
    Jan 2008
    Messages:
    744
    Location:
    NEW JERSEY
    I am 99% sure it is wrong and costly course of auction. I'd pull the laser out and cleaned those slit glasses from inside as well as mirrors but very gently.
    How old is your machine? What is the print count? Also, did you check Developer units? Are there voids in "developer brush" on a mag roller that corresponds with image flaws?
     
  7. Chrisio1977

    Chrisio1977 Member

    Joined:
    Feb 2019
    Messages:
    10
    Location:
    Uk
    Hi.

    It's a 242 so it's fairly old no idea on the exact age. Print count is around 1million.

    Black drum and dev are brand new
    Yellow drum and dev are brand new
    Cyan and magenta drums are around 50%

    Everything has been cleaned to within an inch of its life admittedly the laser glasses have not been removed and cleaned however are clean on the outside.

    I'm struggling to understand how I get the exact same print defect across all colours in exactly the same place along with what looks like smudged toner on the transition from solid colour to the faded colour and how this can be considered dirty lasers?

    The only common area that we can see at this point is something hanging down and "brushing" the transfer belt or the transfer belt itself somehow.

    I'm not doubting you or anyone else trying to help but the amount of labour involved in pulling the lasers is considerable and I don't want to go that route without firm reasoning.

    Thanks
    Chris
     
  8. OkiTech

    OkiTech Senior Member

    Joined:
    Jan 2008
    Messages:
    744
    Location:
    NEW JERSEY
    Ok, think this - a piece of debris on a copy glass will cause just a dot if you make a copy from the glass... but if you use ADF and there is a piece of debris on a slit glass trough which document being read, it will come out as a line, not a dot. So an obstruction of the beam will cause a void line trough the page because whole thing is in motion and defect is standing still. Can you post a scan of a the same page rather than a pic, it is likely taken under angle. is void continues from color to color in the same line? I can't clearly determine that. is line in Magenta a continuation of a line in Cyan that continues in to yellow? is black color affected at all?
     
  9. Chrisio1977

    Chrisio1977 Member

    Joined:
    Feb 2019
    Messages:
    10
    Location:
    Uk
    Hi.

    I will scan the pages in tomorrow. Just to be clear though, they are individual colour pages just pushed together for the picture.

    Black is affected but for some reason is harder to see the deletions.


    Thanks
    Chris
     
  10. adriansto

    adriansto Senior Member

    Joined:
    Apr 2011
    Messages:
    136
    Location:
    somewhere in europe, near Black Sea
    You can make a try to panic stop the machine and check image on drums.
    If there is ok , before change of belt you can remove the silver patch and reglued it on other part of the belt - 5-6 inch right from old position.
    Your tech must have silver patch as spare or you can make it from aluminium foil.
    Can be internal defect of the belt or not.
     
  11. Biggs

    Biggs Member

    Joined:
    Mar 2017
    Messages:
    94
    Location:
    Edison, NJ
    If the ITB didn't show some major, obvious defect, i don't believe the belt is the problem. And i've never seen a liner void of that nature from a transfer belt.
    I LOOKS like a scratched drum to be honest.. but multiple drums? it's a tough sell. Unless a stationary object is contacting the drums during their rotation, i don't see how that could occur. I would give them a visual inspection just for the hell of it.

    do the void line continue indefinitely? or do you see breaks in the lines before they repeat? do you see the lines coming and going, or carrying in any way? IE, sometimes the line is dashed a bit, sometimes it's 3 short lines as posed to one long line, things like that? That would let me believe perhaps something is grazing the ITB intermittently, perhaps it's cleaning station is failing to fully disengage.

    This would be an obvious solution, but a chunk of something on the charge grids could also cause this, or a bad set of wires.
     
  12. Biggs

    Biggs Member

    Joined:
    Mar 2017
    Messages:
    94
    Location:
    Edison, NJ
    I mean, the more I look at it, the more it looks like a REALLY bad set of corona wires. But that would have any techs first go-to for streaking/banding in the run direction.
     
  13. Chrisio1977

    Chrisio1977 Member

    Joined:
    Feb 2019
    Messages:
    10
    Location:
    Uk
    Apologies for the delay - attached is the PDF version of the print outs.
    As predicted the xfer belt made no difference at all however still happy its been changed as it was showing definite signs of wear.

    The lines will continue for the full length of the print in the print direction - as will the smudges which you can see at the top of the scan
    The lines are there in the yellow just not as noticeable and also there in the black but barely visible.

    For clarification this is whats been done.
    transfer belt cleaning blade cleaned
    transfer belt changed
    everything cleaned externally (ros units haven't been removed to be cleaned)
    Machine stopped mid print and image on transfer belt confirms that its before the fuser and the image on the belt has the white streaks.
    drums swapped about to rule out drum problems.

    I firmly believe there is something hanging down and stroking the belt but we can't find anything at all.

    occasionally there will be a couple of good prints but then it comes back as quick as its gone.

    Thanks
    Chris
     

    Attached Files:

  14. adriansto

    adriansto Senior Member

    Joined:
    Apr 2011
    Messages:
    136
    Location:
    somewhere in europe, near Black Sea
    When you make magenta proof where you see the lines on belt, on top of the belt or on paper transfer area ( before BTR2) ?
     
  15. Biggs

    Biggs Member

    Joined:
    Mar 2017
    Messages:
    94
    Location:
    Edison, NJ
    Perhaps try a series of image stops on the belt in attempt to locate an unscathed image. If no such image can be found, I have to say something is happening further upstream. Does this particular xerox have the drums together with the charge units and developing station? IE replacing the drum replaces the grids/wires and developer?

    If you do find an image unscathed, perhaps try manually rotating the image on the belt until the defect occurs
     
  16. Biggs

    Biggs Member

    Joined:
    Mar 2017
    Messages:
    94
    Location:
    Edison, NJ
    And is it just me, or is yellow perfectly fine? The defect in C and M are most certainly identical. It must be something contacting the belt. In my Canon we once had a warped patch sensor that was grazing the ITB
     
  17. Chrisio1977

    Chrisio1977 Member

    Joined:
    Feb 2019
    Messages:
    10
    Location:
    Uk
    When we stopped the machine mid print the image was on the top of the belt and the defects were still there on the on the image.

    The defects are still there on the yellow but much harder to see however the "smudging" at the edge is evident in the yellow and the other colours. All the defects are contained in this centre section and either side the prints are perfect. I think the next steps are to take out all the draws entirely to get a clear shot of the inside and check for debris.
     
  18. Chrisio1977

    Chrisio1977 Member

    Joined:
    Feb 2019
    Messages:
    10
    Location:
    Uk
    The drums are separate to the devs on this machine and each drum has it's own charge roller. There is a corotron on the black drum that is replaced with each black drum change and I have a old black drum i could try just to see if it's that.
     
  19. Biggs

    Biggs Member

    Joined:
    Mar 2017
    Messages:
    94
    Location:
    Edison, NJ
    I wouldn't bother. The scratch marks are identical. It's not existing within any individual imaging unit. Something must be contacting the belt at some point. Downstream, after the final drum unit, and before transfer to the paper.
     

  20. adriansto

    adriansto Senior Member

    Joined:
    Apr 2011
    Messages:
    136
    Location:
    somewhere in europe, near Black Sea
    Remove all drums module (very sensitive to the lights ) , and check the boottom of every module, remove the draw of the drums module and check carefully. At top of the belt the only contact is with surface of the drums. From the other side of the belt the btr rollers is in contact with the belt.
     

Loading...