Why ask why?

Collapse
X
Collapse
 
  • Page of 1
  • Time
  • Show
Clear All
new posts
Previous template Next
  • blackcat4866
    Master Of The Obvious

    Site Contributor
    10,000+ Posts
    • Jul 2007
    • 22929
    #1

    Why ask why?

    Ok. So it's an eS3040C. The symptom was C3B0, and that part was fairly apparent. The yellow developer was entirely detoned, but most of the ferrite seemed to be retained.

    eS3040 E3B0 yellow detoned.JPG

    Like most of my calls I totally stumbled upon the solution. When I pulled out the imaging unit, the grid tensioner fell out on my shoe. I thought: "I'm probably going to need that." One of my call strategies is to take care of the obvious things, and often the less obvious things resolve themselves. So I repaired the grid tensioner and refit the charge unit. It isn't the first time that I've had the opportunity to repair that microscopic plastic pin that the scorotron spring hooks to. I briefly considered changing out the yellow developer ... but the coverage on the developing roller looked good, just lacking toner. On a whim, I re-assembled the imaging unit like it was and powered up.

    On initializing the machine showed adding toner. Within 10 seconds it had yellow toned back up, and looked fine.

    So here's my question: Can anybody explain why the lack of yellow primary charge might cause the developer to completely detone? And when the charge was restored, why it immediately toned back up?

    A large fraction of my copier theory knowledge is based back in the analog days, and doesn't seem to cover this situation. Anybody? =^..^=
    Last edited by blackcat4866; 01-15-2016, 04:27 AM.
    If you'd like a serious answer to your request:
    1) demonstrate that you've read the manual
    2) demonstrate that you made some attempt to fix it.
    3) if you're going to ask about jams include the jam code.
    4) if you're going to ask about an error code include the error code.
    5) You are the person onsite. Only you can make observations.

    blackcat: Master Of The Obvious =^..^=
    Tags: None
    • Mr Spock
      Vulcan Inventor of Death

      1,000+ Posts
      • Aug 2006
      • 2064
      #2
      Re: Why ask why?

      No charge = total coverage, so just a few dozen copies or a couple of minutes of calibration, is all it takes to empty the dev unit of toner.

      if you did not "change" any counters then it will start adding till the dev sensor is back to normal.
      And Star Trek was just a tv show...yeah right!

        Comment

        • NeoMatrix
          Senior Tech.

          2,500+ Posts
          • Nov 2010
          • 3514
          #3
          Re: Why ask why?

          Interesting...


          To answer the question I would have to see the circuit diagram for this machine.

          Does the Drum charge corona and Dev bias run on the same circuit ?
          If there is no primary charge current, is the Dev bias getting extra current in the circuit ?

          I'm guessing without a primary charge corona running current to the drum, the developer Bias current would probably charge the drum just enough while at the same time discharge toner out of the developer unit.

          The developer(iron powder) itself will sometimes dump from the dev unit if drum is over charged, or if there is no developer bias current present. In your particular case the developer is still in tact in the dev unit, which has me believe it was the dev bias charging the drum and discharging toner from the dev unit.

          Back in the old analogue Microfiche reader/printers days the copy imaging process was all in reverse.
          Where there was black on the microfiche film, the image process would use an opposite charge polarity to
          reverse the image to white, and convert the white microfiche areas over to black toner to print on the paper.

          Interesting, maybe the Toshiba factory guru's can answer this for us ???
          Last edited by NeoMatrix; 01-15-2016, 06:29 AM.
          Inauguration to the "AI cancel-culture" fraternity 1997...
          •••••• •••[§]• |N | € | o | M | Δ | t | π | ¡ | x | •[§]••• ••••••

            Comment

            • didi2005
              Trusted Tech

              250+ Posts
              • May 2011
              • 401
              #4
              Re: Why ask why?

              I do know about the fundamental.

              I just know that the charging issue caused the developer to detone where the machine cannot get through the calibration and throwing call for service sign...

              To resolve the issue, I will pour some toner manually to the developer tank in order the pass the calibration and add toner successfully. Otherwise, need to change the developer material.

              Normally, I will change the both front and rear terminal (black) as well which is the cause of the charging issue...

                Comment

                • blackcat4866
                  Master Of The Obvious

                  Site Contributor
                  10,000+ Posts
                  • Jul 2007
                  • 22929
                  #5
                  Re: Why ask why?

                  Originally posted by Mr Spock
                  No charge = total coverage, so just a few dozen copies or a couple of minutes of calibration, is all it takes to empty the dev unit of toner.

                  if you did not "change" any counters then it will start adding till the dev sensor is back to normal.
                  Do'h!!!
                  I can't believe that I missed that. It's so fricken obvious. I'm sure that's exactly it. Thanks for putting me straight.

                  Originally posted by NeoMatrix
                  ... the developer Bias current would probably charge the drum just enough while at the same time discharge toner out of the developer unit. ...
                  I think Mr. Spock hit the mark, but thanks for your comments. Always interesting. =^..^=
                  If you'd like a serious answer to your request:
                  1) demonstrate that you've read the manual
                  2) demonstrate that you made some attempt to fix it.
                  3) if you're going to ask about jams include the jam code.
                  4) if you're going to ask about an error code include the error code.
                  5) You are the person onsite. Only you can make observations.

                  blackcat: Master Of The Obvious =^..^=

                    Comment

                    • Desert Rat
                      Service Manager

                      Site Contributor
                      1,000+ Posts
                      • May 2008
                      • 1089
                      #6
                      Re: Why ask why?

                      Mr Spock did hit the nail on the head. These digital machines use a charge on the drum that repels toner.
                      No charge meant no image on the analogs.
                      I remember from my Kodak days that a dev station without a bias voltage will self bias when the developer
                      station is run. the result was usually a light copy. These were analog machines.
                      When the bias shorted the copy would get heavy background and the print could barely be seen.

                      DR

                        Comment

                        Previous template Next
                        Working...