GR3770 problem with marks from separator

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  • zx81
    Technician
    • May 2009
    • 25

    #1

    GR3770 problem with marks from separator

    i'm hoping someone has a solution for this problem.

    basically the separator is leaving a mark on prints when there is a dense block of ink in the centre of the page (esp on A3)..
    i've adjusted the separator both ways - until the page doesn;t get separated from the drum ---> and the other way so the mark becomes more pronounced (but not enough to tear the mesh on the drum )
    is this because there is another adjustment that can be made to stop this mark appearing (it actually appears as if the bottom of the separator is making this mark)
    or am i asking too much of the machine to print dense blocks of ink esp. close to the edge of the page..

    can anyone help...
  • joelsa12
    Trusted Tech

    250+ Posts
    • Nov 2008
    • 261

    #2
    Many things come to mind....

    First the ink is wet when the seperator is pulling it off the drum. Printing dark ink in the middle and close to the page is not always recommended. Have you turned the origional around so the large block is at the bottom rather than the top? Or tried running Letter as Letter(r). I know this will not work with you issues on A3 but worth a try on the others. Can you hear a puff of air when the paper is coming out of the machine? Air blows through the end of the seperator, and the pump blows this air has a rubber O ring. This O ring will go bad and it will not blow the air any more. There is a fan in the transport section( three belts that transport the paper out) that sometimes gets week. It will not be sucking the paper down fast enough and may cause it to drag on the seperator. All I have for now good luck.

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    • zx81
      Technician
      • May 2009
      • 25

      #3
      unfortunatly the job i was pulling my hair out about has dense dark borders on both sides! i got around it (with only a few marks) was by printing the pages as A4 on an A3 sheet, but this is not ideal..

      i have wondered for a while whether air is being blown through the separator, will check this.. the problem is definately the the bottom of the separator is catching the end of the paper as it comes off the drum so maybe the suction fan under the transport belts is not working too well also..

      thanks for replying

      Comment

      • zx81
        Technician
        • May 2009
        • 25

        #4
        ran test function for fans!

        i did the tests for the separator fan (the one above the separator arm!) and suction fan..
        the separator fan (the one above the actual separator) was fine but the suction fan under the transport area seemed very weak (though i have nothing to compare against as the other gr3770 seemed just as week) but i will take out the transport area when i have a bit of time and have a proper look...

        i will also take the separator bit out and make sure the hole is clear in the separator and that air is coming out.. is this connected to the fan above it in the machine?
        i will study the tech guide and work out where that o ring is!
        cheers for help so far

        Comment

        • joelsa12
          Trusted Tech

          250+ Posts
          • Nov 2008
          • 261

          #5
          O ring

          The o ring is on the back side of the machine behind the MCTL Board. there is a long black hose that goes over to it. Take back off and it will be the smaller board up in the top right hand side of machine

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          • Davisway

            #6
            Re: GR3770 problem with marks from separator

            Are there specific tests for the seperator fan? I have the same issue with the marks on the paper. I was able to remove the hose to the seperator and that seems to blow a bit though I don't think it is very strong. I can't see any way to test the suction on the bottom fan or the blow power to the top fan. thoughts? Thanks!

            Comment

            • ddude
              General Troublemaker

              250+ Posts
              • Feb 2009
              • 473

              #7
              Re: GR3770 problem with marks from separator

              This has always been a problem when printing dark borders or images; when doing your page layout always try to keep the dark images to the rear, and print the darkest side last. SOY INK has made this problem even worse, as the soy ink does not seem to dry EVER-smearing and marking are prevalent with the newer 'friendly' ink.....
              2000 mockingbirds = 2 kilomockingbirds

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