DC250 Streaks in C-M-Y Prints

Discussion in 'Xerox Color Laser Printers & Color Copiers' started by phatman, Jan 17, 2015.

  1. phatman

    phatman Previous User

    Joined:
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    Hi Guys,

    Need some expert advice before I go stripping my machine to fix this, I have a white line in C-M-Y Print picture will give you an idea, The yellow print had a slightly lighter line which cant be seen in the picture, I've read a lot about the ros mirrors needing cleaning but then also about the drums needing replacing I'm a newbie to these machines so any help is greatly appreciated.

    http://postimg.org/image/dki13ng7f/

    Regards,
    Damien
     
  2. Jeff

    Jeff Senior Member

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    Location:
    Michigan
    In your photo I can't tell if it's the digital picture color shift or the print but the blue test patch looks to have a lot of magenta in it too, more of a blue than a cyan.

    Could you print a test patch of 100% cyan and see if the line is there too?

    Drums are interchangeable between C M and Y so the first step to troubleshoot is to swap a drum between colors and see if the problem follows.
     
  3. phatman

    phatman Previous User

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    Hi Jeff,

    Thank you for your suggestion, Ok so I printed the cyan @ 100% and the line was gone, so then I swapped the cyan drum with the magenta drum but the line was still in the magenta print, So I'm guessing it's not the drum and my next step would be to try and clean the ros?

    Regards,
    Damien
     
  4. Jeff

    Jeff Senior Member

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    Location:
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    The ROS assembly was the only really un-fun thing I had to work on with our docucolor. The problem wasn't the difficulty but it was time consuming to take the whole machine apart very carefully, coax the ribbon cables carefully, and then the only way to tell if I had gotten it or not was to put the whole machine together and test. In my case, the third try was the charm and it took most of a day for me to do it the first time and about a half day the third time as I was very careful as I didn't want to mess something else up. (A trained xerox tech did it in about 90 minutes.)
    With that said, with the guidance of a good tech, in my case I eliminated any remote possibilities first that were much quicker to try just in case:

    1.) I looked at the developer assembly to see if there were any uneven areas on the magnetic "brush" roller and even switched the developer housings between colors while covering the toner inlet on the two switched housings with clear tape to run two test prints (so when I switched C and M developer assemblies a little M toner ended up on the clear tape but didn't contaminate the toner color in the housing... only run a couple test prints this way!) I did have black developer assemblies fail on me twice in 1.5 million prints, but when it was the ROS this wasn't my problem. Fairly quick to test though compared with getting to the ROS.

    2.) Checked the 2nd BTR rollers under the transfer belt. This also wasn't my problem, but it was fairly easy to take a look, give it a quick clean, and switch to test.

    3.) Used a swab to clean the underside ROS windows by taking out the ITB belt drawer and reaching in and cleaning the slot. This also wasn't my problem, but it was fairly quick to try cleaning it from the bottom side compared with taking the whole machine apart. In my case the toner had worked itself into the ROS assemblies themselves, possibly because I didn't change the ozone filter between the machine and the feeder as often as I should have.
     
  5. Jonnan

    Jonnan Member

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    Hello,

    Looks like the magenta developer assembly to me as the blue print is mixed with M and not 100% cyan. As mentioned you might be able to see the faulty area on the developer magnetic roll.
     

  6. OkiTech

    OkiTech Senior Member

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    Hi, yes, as previous post says, I'd give 90%+ that you have issue with developer unit(s)
    You'd need to print bands that are 100%, 50%, 25% of CMYK but do so across the page, not lengthwise. This way problem unit can be pinpointed more accurately. Theoretically, you should check the life counters of developers and if they are over 70%+ change them all because if will start to disassemble the machine for each unit individually it will be time consuming and if tech will be called for this - expencive
     
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