Brother MFC9970CDW prints black line

[LTTP]

Hi, im having troubles fixing one of these machines, problem is about 2 months old and im absolutely sick of it.

This is what ive done so far to try to fix this problem.

1- At first we thought the problem was with the refilled toner cartridges so we bought brand new compatible ones, and problem returned after 2 weeks aprox.

2- Then we cleaned the machine completely, drum units, fuser, rollers, transfer belt, toner waste unit, corona wires and the full toner "car" unit. Problem returned after 2 weeks aprox.

3- We replaced all 4 drum units with brand new generic ones, and again cleaned the machine completely, and this time we put new compatible toner cartdriges, problem returned after 2 weeks.

4- last time i only cleaned and polished all 4 drum units and this time i noticed something rather unusual ive never seen with any other drum ive ever cleaned or polished, the towel i used to polish it, got stained with some strange ambar substance wich is the same color of the drums (picture attached) it looks like the drum is melting, and after a good polish prints were just fine until yesterday when the same problem returned.

What i find strange is that the black line only appears ALWAYS on the left side, sometimes is wider than others but only on the left side. My only thoght is that maybe the heat roller is done and thats causing the black line, machine has 350,000 prints and from what the guys at the office say it has never been serviced, i cant be sure since i only have 1 year working here.

Any ideas on what could be the cause? prints have that black line and also some ghosting that can be seen in the pictures.

[Dickie]

It is offsetting. stop a page half way through the fuser and see if offset is on the unfixed area.
If it is then it is obviously drum, if not then fuser.
I notice all you are using is generic consumables.
I would be prepared to guess that if you put a set of Brother drums and toners in the machine it will be cured instantly !!!!

[Blizzoo]

If customer don't want original toner fitted you can change the paper type to a thicker size and offsetting may disappear but copy speed will decrease...

[LTTP]

If customer don't want original toner fitted you can change the paper type to a thicker size and offsetting may disappear but copy speed will decrease...

Well customer is actually my boss LOL so he doesnt want to buy orginal toner, i had a hard time convincing him to buy new compatble ones so...

Anyways thank you guys for your input, ill try to change the thickness of the paper to see if issue at least decreases.

Just one thing, English isnt my motehr language so im not fully understangding what OFFSETTING means in this case, could you explain to me whats actually happening inside the machine for that nasty black line to appear on the paper?

EDIT: well i just did some testing changing paper thickness and problem persists, also checked that the black stain comes BEFORE entering the fuser unit, i turned the machin off while a page was just entering the fuser and paper had that nasty line from top to bottom, so at least now i can rule out a problem with the heating roller.

Could the transfer belt be the casue of this? black line is only on the fron ot every print tho, back of the paper is completely clean. Illl try to find OEM drum units loose, all i could find so far is the whole drum-toner cartdrigde assy.

[JRCS]

Well customer is actually my boss LOL so he doesnt want to buy orginal toner, i had a hard time convincing him to buy new compatble ones so...

Anyways thank you guys for your input, ill try to change the thickness of the paper to see if issue at least decreases.

Just one thing, English isnt my motehr language so im not fully understangding what OFFSETTING means in this case, could you explain to me whats actually happening inside the machine for that nasty black line to appear on the paper?

EDIT: well i just did some testing changing paper thickness and problem persists, also checked that the black stain comes BEFORE entering the fuser unit, i turned the machin off while a page was just entering the fuser and paper had that nasty line from top to bottom, so at least now i can rule out a problem with the heating roller.

Could the transfer belt be the casue of this? black line is only on the fron ot every print tho, back of the paper is completely clean. Illl try to find OEM drum units loose, all i could find so far is the whole drum-toner cartdrigde assy.

Offsetting = doble imagen

minnesotacopier

[jimmcgee]

The black line is just the offsetting (reprinting of the original image) of the border on the printed image. If you look at the reprint of menu and measure back to the original print, then divide by 3.14, you will get the diameter of the roller that is offsetting. my guess is about 30-35mm, which would make it the drum as the fuser rollers on that model are only about 20mm. My best guess is the compatible toners you are using. Brother refills/compatibles commonly cause this problem as the drum cleaning system is a brush rather than a blade so charge voltage etc. is critical. If cost is an issue then the machine is probably being over used, and you should tell your boss to upgrade to something that will run cheaper. Good luck.