Brother MFC-8950DW Paper Jam Issue

[Natebond]

I am trying to repair printer for a client. They had brought in the printer because it was not crinkling papers in large print jobs and during those large print jobs the toner wasn't always properly fused to the paper. The fuser roller was very wrinkled which upon further research was suggested to be replaced. The replacement fuser assembly worked great. The only issue client reported was that duplex pages often had toner splotches on the back. This problem was cause by when toner leaking into the printer when the client transported it back to their location. It was brought back into the shop and one of the techs sprayed out the inside of the printer with compressed air. It printed fine for a few pages and it did appear to correct the issue with the toner splotches, however we noticed an increase in paper jams. The printer now jams after only printing one sheet. It doesn't matter if it is duplex or single page mode or a copy job or a print job. The results are always the same. The first page prints and then the second page will be partially through the fuser unit and a third page will be being picked up from the paper tray. The second page is normally about 2-3 inches out of the fuser. What is strange is that the printing on the second page is that it starts about 3 inches lower than what it should be and how it prints on the first page. The printer also reports a paper jam if I am only doing one copy, even though the copy comes through just fine. If I open the printer is does not have any stuck pages when only doing one copy. It also reports this error even if I only have one sheet in the paper tray. These issues happen both in the regular paper tray and the manual feed tray.
I did try the old fuser unit again and the paper jam issue occurs with that as well.

Any input would be great. Thank you for your help!

[Dickie]

Re: Brother MFC-8950DW Paper Jam Issue

Sounds to me that he has blown the excess toner into the exit switch sensor.
It's never a good idea to blast air duster randomly inside machines as all it does is move toner from one place to another and this, I suspect, is the root of your problem.
Take it apart and clean it properly

[Natebond]

Re: Brother MFC-8950DW Paper Jam Issue

I completely agree about the compressed air. It was done on a day I wasn't in. In either case I looked through the service manual for the exit switch sensor and wasn't able to find it. Would it be listed under a different name? Or could you just let me know the location.

I've never worked on this model of printer before. What is your suggested approach to disassembly for cleaning?

Thanks for your help!

[Printerdude]

Re: Brother MFC-8950DW Paper Jam Issue

This sound more of a registration problem than a exit problem, since you mention the second page print is three inches from the top of the page and both trays are having the same problem. Look inside the printer where the paper travel before going into the drum unit, there should be two paper sensor flag, if not that is your problem. Other problem could be the drum unit or toner cartridge. Are they using OEM supplies? If problems still occurs, then the main drive might have an solenoid issue.

[Natebond]

Re: Brother MFC-8950DW Paper Jam Issue

I see two pieces of plastic that are both popped up which I believe are the two paper sensor flags. I can depress them without issue. They appear to move freely. They use third party toner and drum, though both were working without issue before the compressed air.

Let me know if I should look another place.

[Natebond]

Re: Brother MFC-8950DW Paper Jam Issue

Here are pictures of the problem.
Often after the paper jam the next sheet that successfully prints has toner smudges on it, but that it likely due to the additional toner that was on the drum not adhering to page since the second page is always aborted. Does this sound correct?

[Elmtech]

Re: Brother MFC-8950DW Paper Jam Issue

Try cleaning the registration sensors not just the sensor flags. Sounds like toner is blocking the optical path. If you want to check individual sensors you can run the sensor check in maintenance mode it may show a delayed sensor or a faulty one.

[Printerdude]

Re: Brother MFC-8950DW Paper Jam Issue

Here are pictures of the problem.
Often after the paper jam the next sheet that successfully prints has toner smudges on it, but that it likely due to the additional toner that was on the drum not adhering to page since the second page is always aborted. Does this sound correct?

The additional toner may be coming from the fuser rollers, the drum have a cleaning blade.

[Elmtech]

Re: Brother MFC-8950DW Paper Jam Issue

Brother drum units have no cleaning blade.

[Printerdude]

Re: Brother MFC-8950DW Paper Jam Issue

I see two pieces of plastic that are both popped up which I believe are the two paper sensor flags. I can depress them without issue. They appear to move freely. They use third party toner and drum, though both were working without issue before the compressed air.

Let me know if I should look another place.

Try enable one sensor at a time with supply in and see if you get a paper jam message, this will tell you if the sensor is working. As far as the exit sensor flag goes, it is located on the door that is attached to the fuser assembly. Did the tech use compressed air on the drum unit? Make sure the guides after the drum unit and before the fuser assembly are clean or not broken, possible paper delay before reaching the fuser.

[Natebond]

Re: Brother MFC-8950DW Paper Jam Issue

Here are the results of the sensor test:
C1 TNNT
CVRCPORMRAMP24
DFDR AC DB

When I pushed stop/end it said Drum Error

The tech did use compressed air on the drum. I will look into the sensors tomorrow.
I'm having trouble finding the registration optical sensors.

Printerdude. What do you mean when you say "Try enable one sensor at a time with supply in?" What do you mean by supply in?

Thanks everyone for your help so far!

[Printerdude]

Re: Brother MFC-8950DW Paper Jam Issue

I meant taping sensor flag down so it can detect a paper jam, just to see if the sensor is working. Do one flag at a time.

[Printerdude]

Re: Brother MFC-8950DW Paper Jam Issue

Brother drum units have no cleaning blade.

My bad.

[tech28]

Re: Brother MFC-8950DW Paper Jam Issue

Bad fuser, some newer brothers have a sleeve instead of a roller, the sleeve slips, Brother had an extended warranty for that problem for up to 2 years from 1 year. Also, those fusers have a lower roller that has rough ends to help the fuser exit copies out, when there is slight hesitation in upper rotation, jam occurs. Could be running number of copies/prints, jams will occur. Good Luck.

[Natebond]

Re: Brother MFC-8950DW Paper Jam Issue

I taped down the two internal sensor flags separately and both reported a paper jam. I taped the exit sensor flag and it reported a rear paper jam.
Printerdude, I assumed you meant either the metal guide or plastic fins in reference to your comment "guides after the drum unit and before the fuser assembly are clean or not broken". Is that correct?

Elmtech, you had mentioned "Try cleaning the registration sensors not just the sensor flags. Sounds like toner is blocking the optical path." Where is the registration sensors and optical path located? Also I posted the results of the sensor test above. Did this reveal any issues?

Since the fuser was just replaced I'm don't believe that it's faulty. Also I tried the old fuser and the issue is still occurring. The issue started only after the printer was blown out with compressed air.

Thanks!