Instructables

Paper Shredder won't stop

Ativa MDM 8000 in auto mode should time out and turn the motor off after last shred but no longer does this, just keeps running. Took apart and cleaned all sensors but did not help. Checked all wiring, looked OK.  Any ideas how to fix ? Must be a problem with circuit board.

canucksgirl2 years ago
I'm guessing you bought this from Office Depot? If so, when did you purchase it? They have a 1-year limited warranty on parts and a 5 year limited warranty on the cutters. If you call the store, or check your paperwork, you may just get some help. Aside from that, I did some research and all I was able to find is a whole lot of other people with this make/model and other make/models who are complaining of the same issue.

Obviously you said that you took it apart and cleaned the sensors. That would be the only suggestion I could give. Unless its a short or something else in the wiring, the sensors are suppose to turn the machine on and off when paper is detected. Obviously if they are dirty or blocked with paper or some other material, they will continue to stay on. Do you have a manual that indicates all the sensor locations? Perhaps there was one you missed?
phantom9 (author)  canucksgirl2 years ago
Contacted Office Depot. Make a long story short I E-Mail my machine receipt and will be getting a store credit in 7 to 8 weeks. They did not indicate the want the unit back so after I get my store credit I may mess around with the printed wiring board at no lost to me. Maybe I will fix it, than again I may really smoke it.
Well that's good to hear. If they don't want it back, most definitely use it for something. There's always good parts to be had for other projects. Then post your project here... there's lots of contests... :)
phantom9 (author)  canucksgirl2 years ago
It is an Office Depot product. I guess that I will dig up the paper work and contact them. I did clean all the sensors but was hopping someone else had the same problem and was able to fix it. Then maybe I could repair my unit. Anyway thanks. Once I resolve this issue with Office Depot I will post the results.
In case its not an easy fix, going back to the place of purchase (especially if its still under warranty) is a good idea. - Let us know what happens.
TanquerayG1 year ago
I figured it out pretty certainly and found a workaround.

I used a camera to look at the two LEDs that are paired up with the two sensors in the dark to see if they are working. I assumed they are infrared and I knew that shows on a camera. I saw the LED for the main paper shred slot was bright but the one for the CD slot was very dim.

I tried getting the CD LED and sensor close together and it didn't fix it.

Then I remembered that photo sensors increase/decrease resistance with light. I suspected the resistance decreases when light hits it so a short of it's two leads may act as if the LED was being received well. I shorted out the sensor of the CD slot and it worked. The motor stopped and would stop/start based on the other LED/sensor pair being tripped.

I do wonder if it is not this simple and the circuitry is now getting too much current or voltage and burn out. But it worked and I am fixing it this way.
phantom9 (author)  TanquerayG1 year ago
I opened the unit up and by passed the CD/DVD shredder LED, did not work. I than by passed the paper shredder LED and this did work. I had to switch out the LED pairs so that the paper shredder would. control the shredder motor. If I ever want to shred a CD/DVD I guess I will need to feed a sheet of paper through the machine.
Anyway thank you. Let me know that you received this response.
phantom9 (author) 2 years ago
Thanks anyway, sent you an E-Mail. I did a complete tear down and cleaning which did not fix the problem
rickharris2 years ago
I will bet there is a small bit of paper trapped in the middle of the cutters keeping the sensor there on.