Taskalfa 420i dots while scanning

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  • pureflip428
    Junior Member
    • Oct 2015
    • 1

    #1

    [Misc] Taskalfa 420i dots while scanning

    I am working on a machine (TASKalfa 420i has about 182,000 pages printed so far) that has dots while scanning through the document processor. The dots appear only while scanning, and not when copying. The dots are throughout the whole page. Imagine old comics that were illustrated with dots. Sort of like that except a lot smaller dots on the whole page. Scanning is set to send to email. There is a 3500i on the same network that also scans to email same as this machine but has no problems. This is what I have done so far but nothing has fixed the issue so far.
    • I ran maintenance mode
      • Ran U425 & U411

    • Flushed the firmware
    • Replaced ISU
      • replacing the ISU resulted in having only the top half of the page with dots. The bottom half was clear

    • Cleaned slit glass
    • Cleaned white reference strip under plate glass
    • Cleaned all mirrors
    • (all cleaning was with a dry cloth towel)
    • Changed scanning resolution from 200x200 dpi to 600x600dpi
      • Changing the resolution resulted in finer or smaller dots on the page. Imagine zooming out on the page.

    Since the new ISU did not fix the problem, the old one was put back in and left with the following scan settings.
    • File Format : PDF
    • Resolution : 600x600dpi
    • Quality : Text + Photo

    Attached is a scan of a print of what was scanned. (Machine is not at my location and I was not able to scan straight to my own email)
    Attached Files
  • Kyo fan
    Trusted Tech

    250+ Posts
    • Dec 2013
    • 368

    #2
    Re: Taskalfa 420i dots while scanning

    I've had something similar to this and it was that i left the mirrors not aligned after i cleaned them. Check the mirrors, and press each down on both ends. You said you did U411 (Adjust DP automatically). Do you have all 3 charts needed for it?

    Comment

    • kjg
      Trusted Tech

      100+ Posts
      • Mar 2009
      • 111

      #3
      Re: Taskalfa 420i dots while scanning

      Try scanning something not printed on the 420i and see if you still have the dots.
      I have seen that before on machines going back to falcon II's scanning printed documents.
      It may be picking up background on the print you have made. You may need to adjust print density or do gray adjust.

      Comment

      • copydocinc
        Trusted Tech

        Site Contributor
        250+ Posts
        • Mar 2015
        • 263

        #4
        Re: Taskalfa 420i dots while scanning

        I'm wondering if it does it when laying page on the glass, instead of the doc feeder. If not, that would eliminate a few things.
        and
        Look closely at the scanned copies of the same document to see if the dots are uniform or random from one page to the other, if uniform the post above has merit, that the original being scanned isn't clean.

        Comment

        • SamuelBlake72
          Junior Member
          • Jan 2018
          • 5

          #5
          Re: Taskalfa 420i dots while scanning

          I am having the same problem with a 3500i. We have tried the sata cable from the main PCB to the scanner board. Have also tried replacing both boards. Lost on what to do next. Problem occurs when scanning a document either to doc box or to folder and email from glass or df.

          Comment

          • sparkycivic
            Trusted Tech

            250+ Posts
            • Apr 2017
            • 348

            #6
            Re: Taskalfa 420i dots while scanning

            does it happen when you scan a clean sheet of new paper?

            how clean is the machine environment?

            Comment

            • SamuelBlake72
              Junior Member
              • Jan 2018
              • 5

              #7
              Re: Taskalfa 420i dots while scanning

              Yes it happens with a blank piece of paper. The machine environment is very clean. It is in a bank that get cleaned everyday.

              Comment

              • sparkycivic
                Trusted Tech

                250+ Posts
                • Apr 2017
                • 348

                #8
                Re: Taskalfa 420i dots while scanning

                is it a dual scanning document processor or reversing?

                Comment

                • SamuelBlake72
                  Junior Member
                  • Jan 2018
                  • 5

                  #9
                  Re: Taskalfa 420i dots while scanning

                  Reverse. But it does it off the glass as well.

                  Comment

                  • sparkycivic
                    Trusted Tech

                    250+ Posts
                    • Apr 2017
                    • 348

                    #10
                    Re: Taskalfa 420i dots while scanning

                    besides making sure the optics are perfectly clean, maybe the lamp or ccd need replaced?
                    I'm out of ideas...

                    Comment

                    • SamuelBlake72
                      Junior Member
                      • Jan 2018
                      • 5

                      #11
                      Re: Taskalfa 420i dots while scanning

                      Ok we will try that next and hopefully we get some results.

                      Comment

                      • Reed
                        Senior Tech

                        Site Contributor
                        250+ Posts
                        • Feb 2011
                        • 250

                        #12
                        Re: Taskalfa 420i dots while scanning

                        I had a same problem on a Muratec machine. I ended up changing the document scan type from "auto" to "text" and it took care of the problem. Maybe you could try something similar with the Kyocera.

                        Comment

                        • SamuelBlake72
                          Junior Member
                          • Jan 2018
                          • 5

                          #13
                          Re: Taskalfa 420i dots while scanning

                          We have done this. It doesn't show the dots while on full color scans but it has a pink band which doesn't work due to it being a bank.

                          Comment

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