bizhub C450i dark on back side

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  • jwai
    Trusted Tech

    250+ Posts
    • May 2018
    • 497

    bizhub C450i dark on back side

    Hello,

    One customer reported some black lines on printout.
    We checked the problem due to cleaning blade of drum unit K, after we replaced that blade and tested, issue fixed.
    However we found approx. 5cm width grey image on back side while they got 1-sided printing, tested another drum unit K from another normal machine still same.
    Any idea about that?

    ( Drum unit K life 60% left, developing unit K 80% left )
    Attached Files
  • Gift
    Service Manager

    1,000+ Posts
    • Mar 2011
    • 2412

    #2
    Re: bizhub C450i dark on back side

    I can see BK background on the entire page, rear end ist just worse and more visible.
    Does the effect shift towards colored background if you run high coverage with cyan for example?

    If yes: ITB cleaning might be insufficient
    If no: My guess is that this is an issue caused by compatible / non original consumables causing background on the drum wich ends up via ITB on the paper transfer roller.

    Comment

    • jwai
      Trusted Tech

      250+ Posts
      • May 2018
      • 497

      #3
      Re: bizhub C450i dark on back side

      Originally posted by Gift
      I can see BK background on the entire page, rear end ist just worse and more visible.
      Does the effect shift towards colored background if you run high coverage with cyan for example?

      If yes: ITB cleaning might be insufficient
      If no: My guess is that this is an issue caused by compatible / non original consumables causing background on the drum wich ends up via ITB on the paper transfer roller.
      We took the replaced cleaning blade drum unit to another good machine, didn't have this.

      Comment

      • jwai
        Trusted Tech

        250+ Posts
        • May 2018
        • 497

        #4
        Re: bizhub C450i dark on back side

        Originally posted by Gift
        I can see BK background on the entire page, rear end ist just worse and more visible.
        Does the effect shift towards colored background if you run high coverage with cyan for example?

        If yes: ITB cleaning might be insufficient
        If no: My guess is that this is an issue caused by compatible / non original consumables causing background on the drum wich ends up via ITB on the paper transfer roller.
        I scanned it with darkest density and background removal for easier visible check.
        Just approx 5cm bar on leading edge direction, remaining area is white.

        Comment

        • 4Toon
          Technician

          50+ Posts
          • Mar 2023
          • 90

          #5
          Re: bizhub C450i dark on back side

          Originally posted by jwai
          We took the replaced cleaning blade drum unit to another good machine, didn't have this.
          Transfer belt, clean auger and blade first then replace if that does not fix anything, what happening is that waste toner is on the belt then will go to the secondary transfer roller then on your page that is why it is on the lead edge then no where else along the back of the page seen this in other brands too.

          Comment

          • allan
            RTFM!!

            5,000+ Posts
            • Apr 2010
            • 5445

            #6
            Re: bizhub C450i dark on back side

            Give the transfer cleaning section a good vacuum and check if its still does the same. Had secondary transfer roller with a old belt do this on other models.
            Whatever

            Comment

            • copier tech
              Field Supervisor

              5,000+ Posts
              • Jan 2014
              • 7931

              #7
              Re: bizhub C450i dark on back side

              Originally posted by jwai
              Hello,

              One customer reported some black lines on printout.
              We checked the problem due to cleaning blade of drum unit K, after we replaced that blade and tested, issue fixed.
              However we found approx. 5cm width grey image on back side while they got 1-sided printing, tested another drum unit K from another normal machine still same.
              Any idea about that?

              ( Drum unit K life 60% left, developing unit K 80% left )
              Replace the complete imaging unit with a new one, not just the blade!
              Let us eat, drink, and be merry, because tomorrow we may die!

              For all your firmware & service manual needs please visit us at:

              www.copierfirmware.co.uk - www.printerfirmware.co.uk

              Comment

              • Lordnixon
                Technician
                • Jul 2017
                • 18

                #8
                Re: bizhub C450i dark on back side

                I have met with this problem. These were unoriginal materials. When mixed, they gave a defect. When changing the toner, it was necessary to run from 200 to 500 pages of full-color fills until the toner was completely replaced (the background disappears or becomes smaller, the stripe on the back side disappears). After that, we clean the drum unit.
                PS: it was a black and white 450i

                Comment

                • jwai
                  Trusted Tech

                  250+ Posts
                  • May 2018
                  • 497

                  #9
                  Re: bizhub C450i dark on back side

                  Originally posted by Lordnixon
                  I have met with this problem. These were unoriginal materials. When mixed, they gave a defect. When changing the toner, it was necessary to run from 200 to 500 pages of full-color fills until the toner was completely replaced (the background disappears or becomes smaller, the stripe on the back side disappears). After that, we clean the drum unit.
                  PS: it was a black and white 450i
                  You said mixture of original and OEM toner?
                  The customer is using genuine toner only.

                  Comment

                  • Lordnixon
                    Technician
                    • Jul 2017
                    • 18

                    #10
                    Re: bizhub C450i dark on back side

                    Originally posted by jwai
                    You said mixture of original and OEM toner?
                    The customer is using genuine toner only.
                    mixture of original TN-628K and TN-619k/Tn616k(+dev)

                    Comment

                    • antone
                      Trusted Tech

                      250+ Posts
                      • Oct 2014
                      • 344

                      #11
                      Re: bizhub C450i dark on back side

                      HV PWA FIXED MIND

                      Sent from my SM-S918U using Tapatalk

                      Comment

                      • jwai
                        Trusted Tech

                        250+ Posts
                        • May 2018
                        • 497

                        #12
                        Re: bizhub C450i dark on back side

                        Originally posted by antone
                        HV PWA FIXED MIND

                        Sent from my SM-S918U using Tapatalk
                        Fixed issue by replaced PWB-HV?

                        Comment

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