Designjet Z6100 banding

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  • theengel
    Service Manager

    1,000+ Posts
    • Nov 2011
    • 1784

    Designjet Z6100 banding

    I'm getting banding with all colors. Replaced some printheads (the ones with bad nozzels), ran head alignment, and ran paper advance calibration. Also tried adjusting paper advance. None of it seemed to make a difference.

    When I print out the test pattern, it looks kind of weird. I shot a video of it while it prints and am posting it below. You'll have to skip to the middle to see what I'm talking about, but you can see these white spaced while it's printing. I don't think I've seen one do this before.

  • qbert69
    Service Manager

    1,000+ Posts
    • Mar 2013
    • 1152

    #2
    Re: Designjet Z6100 banding

    It's been awhile since I used/worked on an HP inkjet!

    Some manufactures used a dye based as opposed to pigment based ink.

    Are all of your ink cartridges new?....if you have any that are not new and fresh...have been sitting awhile, sometimes the viscosity of the ink can change!...and cause flow problems!

    Just asking questions!

    REACH FOR THE STARS!!!
    Konica Minolta Planetariums!
    https://www.konicaminolta.com/planet...gma/index.html

    Comment

    • Kiran Otter
      Service Manager

      Site Contributor
      1,000+ Posts
      • Dec 2013
      • 1098

      #3
      Re: Designjet Z6100 banding

      I'm not sure I'm seeing the problem. Is it this spot I've pointed to in the image?

      2016-05-06_1132.jpg
      2016-05-06_1132 - Kiran_Otter's library for a larger version (not sure why it's so tiny on the forum)

      Does it do it on different types of media?

      Kiran

      Comment

      • Kiran Otter
        Service Manager

        Site Contributor
        1,000+ Posts
        • Dec 2013
        • 1098

        #4
        Re: Designjet Z6100 banding

        By the way, it might be more helpful to see a picture or scan of the print so we can see the defect in the printed image.

        I'm also going on the assumption you've been through the entire section of the service manual regarding troubleshooting banding issues, cleaning the paper advance (OMAS) sensor and so on. It's very extensive.

        If it is just a white(ish) band near the top of the print near the edge of the media, there's a section of the manual "Defects near the top of a print"; namely you want to set the margins to 'extended' in the settings so the printer does not print so close to the edge of the media.

        This has to do with something called the 'soft landing'; only 4 of the 8 printheads can print near the edge of the media for about 2 inches, and then all 8 kick in.. and you get a defect in the print quality because of the difference in heads being used (as it was explained to me.) So increasing the margin avoids this 'soft landing' effect. Some media is more sensitive to this than others however.

        Kiran

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        • theengel
          Service Manager

          1,000+ Posts
          • Nov 2011
          • 1784

          #5
          Re: Designjet Z6100 banding

          This has to do with something called the 'soft landing'; only 4 of the 8 printheads can print near the edge of the media for about 2 inches, and then all 8 kick in.. and you get a defect in the print quality because of the difference in heads being used (as it was explained to me.) So increasing the margin avoids this 'soft landing' effect. Some media is more sensitive to this than others however.
          I did not know that. Thanks.

          Here's a some pics of the image so you can see it better.

          IMAGE.1.jpgIMAGE.2.jpg

          I will look more at the manual.

          Comment

          • Kiran Otter
            Service Manager

            Site Contributor
            1,000+ Posts
            • Dec 2013
            • 1098

            #6
            Re: Designjet Z6100 banding

            Thanks for the pictures. I don't think it's a printhead issue.. you just have to go through the exhaustive troubleshooting of the paper advance and OMAS stuff in the manual. But do try it on other media.

            What media is this? Is it HP? What is it exactly?

            Kiran

            Comment

            • theengel
              Service Manager

              1,000+ Posts
              • Nov 2011
              • 1784

              #7
              Re: Designjet Z6100 banding

              I believe it's a heavy HP Matt

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              • Kiran Otter
                Service Manager

                Site Contributor
                1,000+ Posts
                • Dec 2013
                • 1098

                #8
                Re: Designjet Z6100 banding

                That media should work very well in the Z6100.

                Kiran

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                • Iowatech
                  Not a service manager

                  2,500+ Posts
                  • Dec 2009
                  • 3933

                  #9
                  Re: Designjet Z6100 banding

                  Just my two cents, but it looks like there's one or more plugged jets in the print head.
                  If I remember correctly, HP wide formats keep track of plugged jets and try to compensate with other jets. It sure looks like that's what that machine in the video is doing.
                  I might be thinking of Canon wide formats, though. It's been a few years since I've seen either of them.

                  Comment

                  • Lance15
                    Service Manager

                    Site Contributor
                    1,000+ Posts
                    • Jun 2015
                    • 1071

                    #10
                    Re: Designjet Z6100 banding

                    I know the solid ink Xerox's do nozzle substitution. Not real sure about HP plotters. Never heard of it, at least.

                    Comment

                    • Kiran Otter
                      Service Manager

                      Site Contributor
                      1,000+ Posts
                      • Dec 2013
                      • 1098

                      #11
                      Re: Designjet Z6100 banding

                      Yes, the HP's do it too. On the Z6x00 you can 'force drop detection' which resets the nozzle health database and starts a new drop detection.

                      I know other models do it as well but the option to reset the data is not available.

                      Kiran

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                      • theengel
                        Service Manager

                        1,000+ Posts
                        • Nov 2011
                        • 1784

                        #12
                        Re: Designjet Z6100 banding

                        This thing is driving me nuts.

                        If you look in the video, about halfway through the big blocks of color, you can see these solid white lines. Those come out as light bands in the end. Kiran mentioned the two lines of printheads, and I thought maybe it was normal and had something to do with that. But that's not the case. I watched another Z6100 do a test page, and it doesn't do that at all.

                        On "tech support's" suggestion, I replaced the carriage unit & carriage board. I didn't have much hope in that, and I was right, it did nothing for me. Still banding. I went through most of the manual's suggestions on banding, and it just doesn't seem like it's helping. When I run the paper advance visual test print, it looks almost normal. There was one line that looked weird, but I think I had tugged on the paper for that one. Everything else looks like it should.

                        Grrr.

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                        • theengel
                          Service Manager

                          1,000+ Posts
                          • Nov 2011
                          • 1784

                          #13
                          Re: Designjet Z6100 banding

                          The type of paper they're using is HP Polypropylene Matte.

                          The manual mentioned types that won't work with the OMAR, and this might be one of them, but I'm not sure where to find out, and how to 'disable OMAR' in the test prints. Also, it said to look for OMAR flashing red, but I'm not sure where I should see this going on. When I run the OMAR Calibration, everything appears to go well, and then at the finish, the machine says "Calibrating PixelSize Offset" and is stuck on that until I turn the machine off. Could I just need a new OMAR?

                          Comment

                          • Kiran Otter
                            Service Manager

                            Site Contributor
                            1,000+ Posts
                            • Dec 2013
                            • 1098

                            #14
                            Re: Designjet Z6100 banding

                            Something I want to note: Always.. always.. try replacing the consumables first before replacing something like a carriage assembly. I know you said you replaced some of the printheads, but I would look at the usage of the others and replace any with either a lot of hours on them, or a lot of ink through them. How much is a lot? 800ml seems to be a lot for these printers, but I've seen heads with 1200-1500ml that were still reasonably functional.

                            I can't see the actual nozzle pattern in the pictures but let's assume they all look decent.

                            Judging by the way the carriage puts down the ink bands.. I'm not sure that's definitive. Depending on the type of media selected, the printer will lay down ink in various ways to achieve the best coverage. Try telling the printer this media is HP HW Coated, or even just Plain Paper, and see if anything changes.

                            Anything from HP that's 'matt' media should be compatible. It would be important though to try other media. I also recommend users keep a roll of 24 or 36" HP HW Coated paper purely for testing and doing print head alignments on. It's cheap and you're not wasting their vinyl or canvas, etc. If the printer prints correctly on the heavy-weight coated paper, then you can rule out printheads, usually.

                            The OMAS (not OMAR is a tiny window in the platen. It's near the 6th platen roller from the right.

                            2016-05-11_1233 - Kiran_Otter's library

                            The manual says it's OK to use alcohol to clean it.

                            If you've fiddled with the calibration settings, I would (and have) always gone into the Paper advance calibration and reset the paper advance. Start from square one and rule out the media and printheads on HW coated paper.

                            Kiran

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                            • Kiran Otter
                              Service Manager

                              Site Contributor
                              1,000+ Posts
                              • Dec 2013
                              • 1098

                              #15
                              Re: Designjet Z6100 banding

                              By the way, if you have access to another Z6x00, borrow the print heads from it and try them in this machine. And vice versa if you want to be really thorough.

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