Thanks Thanks:  0
Dislikes Dislikes:  0
Results 1 to 8 of 8
  1. #1
    Technician
    Join Date
    Sep 2009
    Posts
    40
    Rep Power
    30

    Riso GR 3750 pressure solenoid problem

    I recently replaced a worn pressure lever on my Riso GR 3750 where the solenoid hook kept slipping off. Now the solenoid hook does not activate most of the time. In test mode 68 it works fine though. I have videod the problem showing how the paper feed fails after a few cycles and the failure of the solenoid hook to activate after a few cycles (see below). More often than not the solenoid doesn't activate and the hook doesn't enage with the pressure leaver.
    Does anyone have any suggestions as to what the problem mght be other than a faulty solenoid in need of replacement.

    Thanks.

    Ian


  2. #2
    Not a service manager 2,500+ Posts Iowatech's Avatar
    Join Date
    Dec 2009
    Location
    Iowa
    Posts
    3,933
    Rep Power
    97

    Re: Riso GR 3750 pressure solenoid problem

    Actually, the pressure solenoid is activated unnecessarily most of the time and my first guess about why that is because there's not enough clearance between the pressure lever and the pressure hook at the top of their travel. There should be a millimeter of clearance then. That's actually pretty important, you should look into that.
    Thanks for the video!
    Last edited by Iowatech; 08-24-2016 at 01:16 AM.

  3. #3
    Technician
    Join Date
    Sep 2009
    Posts
    40
    Rep Power
    30

    Re: Riso GR 3750 pressure solenoid problem

    Quote Originally Posted by Iowatech View Post
    Actually, the pressure solenoid is activated unnecessarily most of the time and my first guess about why that is because there's not enough clearance between the pressure lever and the pressure hook at the top of their travel. There should be a millimeter of clearance then. That's actually pretty important, you should look into that.
    Thanks for the video!
    I checked the clerarance and that is OK. In test mode 68 the hook tips forward and I guess thisis what it needs to do to engage with the pressure leaver, but it isn't. I wonder if the signal from the paper sensor isn't coming through consistently.

  4. #4
    Field Supervisor 500+ Posts 20gaugeO/U's Avatar
    Join Date
    Feb 2009
    Posts
    547
    Rep Power
    41

    Re: Riso GR 3750 pressure solenoid problem

    The 2 wires to the solenoid used to break at the big looping bend in the middle. I can't tell if there is clear shield around the wires but if there is cut it off and stress pull the wires and see if they are hanging by a thread. Can always solder back together if they break.

    Next would probably be the paper in sensor area. Nick in the paper feed mylar or the paper In sensor is failing. If you test the paper in sensor in service mode and it goes from fast beeps to slow beeps (change of states from detecting paper) that's good. But if you move the paper quickly under the sensor I used to be able to get a bad sensor to "wig-out" and do fast and slow beeps at same time. A couple fast beeps, then a slow one, then a couple fast, then a slow one -- with the paper removed.

    Next check and see if the drum is spinning internally. That can cause weird timing issues if it isn't spinning as it should.

  5. #5
    Technician
    Join Date
    Sep 2009
    Posts
    40
    Rep Power
    30

    Re: Riso GR 3750 pressure solenoid problem

    Quote Originally Posted by 20gaugeO/U View Post
    The 2 wires to the solenoid used to break at the big looping bend in the middle. I can't tell if there is clear shield around the wires but if there is cut it off and stress pull the wires and see if they are hanging by a thread. Can always solder back together if they break.

    Next would probably be the paper in sensor area. Nick in the paper feed mylar or the paper In sensor is failing. If you test the paper in sensor in service mode and it goes from fast beeps to slow beeps (change of states from detecting paper) that's good. But if you move the paper quickly under the sensor I used to be able to get a bad sensor to "wig-out" and do fast and slow beeps at same time. A couple fast beeps, then a slow one, then a couple fast, then a slow one -- with the paper removed.

    Next check and see if the drum is spinning internally. That can cause weird timing issues if it isn't spinning as it should.
    Thanks for those suggestions. I'll have a look in a couplke of days when I have some time.

  6. #6
    Technician
    Join Date
    Sep 2009
    Posts
    40
    Rep Power
    30

    Re: Riso GR 3750 pressure solenoid problem

    Thanks to all. I re-checked and adjusted the timing properly and things have improved. Now if I can only solve the master removal problem....

  7. #7
    Not a service manager 2,500+ Posts Iowatech's Avatar
    Join Date
    Dec 2009
    Location
    Iowa
    Posts
    3,933
    Rep Power
    97

    Re: Riso GR 3750 pressure solenoid problem

    Where does the old master get stuck?

  8. #8
    Technician
    Join Date
    Sep 2009
    Posts
    40
    Rep Power
    30

    Re: Riso GR 3750 pressure solenoid problem

    It isn't lifting off the drum. I have replaced the master removal hooks as one was broken. There's been some improvement with correction of the timing as it does now occasionally remove a master successfully, but more often than not I end up taking the drum out to remove it manually.

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Get the Android App
click or scan for the Copytechnet Mobile App

-= -= -= -= -=


IDrive Remote Backup

Lunarpages Internet Solutions

Advertise on Copytechnet

Your Link Here