Brother MFC 9330 CDW and the mystery of the unwanted embossing marks (a.k.a. fuser replacement)

Written by Claudio Kuenzler - 4 comments

Published on January 21st 2021 - last updated on January 22nd 2021 - Listed in Hardware Office

When my Brother MFC 9330CDW started to print papers with embossing marks (with the shape of a corn plant - but that may just be my imagination) on it, something was definitely not printing as it should.

Brother MFC 9330 CDW leaving marks on papers

But what would cause these horizontally re-occurring marks?

I publicly asked this question on Twitter and received good comments. At the end it turned out to become a real-live streaming troubleshooting thread.

Toner drum units and transfer belt check

The first thought was that there is something sticking out or laying on the transfer belt. After removing the cartridge (toner) units, the transfer belt unit can be lifted off and taken out of the printer. Although used, the transfer belt had nothing on or in it, which would explain these marks:

Additionally to this, all toner/cartridges were checked that they correctly "snapped" into the drum units.

According to visual verification (and to comments on the mentioned Twitter thread) the problem must be elsewhere.

Focus on the back of the printer

When I opened the back of the printer - this is where the fuser unit is placed - I immediately saw something which should not be there: Some broken-off pieces laying there next to the fuser roll.

Brother MFC 9330 CDW pieces in the fuser unit

I removed these two pieces. But the question is: Where did these pieces come from? From what part did they break off? This is where my focus shifted towards the "inner" roll of the fuser, the roll in black:

Brother MFC 9330 CDW defect in fuser unit

A look closer at the "shape" of this defect, seemed to confirm the "corn plant" on the printed pages. And due to the fact that this is a roll, the horizontal re-occurring "stamp" on the papers is explained, too.

Replacing the fuser unit

A replacement for the fuser unit (Brother product ID LY6754001) was ordered for CHF 138 (USD 155 with todays FX rate) and I got it a day later (delivery times have certainly improved in the last decade!).

Next step: Replacing the fuser unit. Luckily there's a great video by Hermes Lara on Youtube which shows how to remove the fuser and place the new unit back into the printer. I strongly suggest to look at that video and do the replacement while watching it.

Note: The video is for the MFC 9340CDW, which is a bit newer than my MFC-9330CDW. But the pieces and the replacement methods are the same.

The printer without the fuser unit:

Brother MFC 9330 CDW back without the fuser unit

... and with the new fuser unit built in:

Brother MFC 9330 CDW fuser replaced with new one

Right after this, the printed pages looked correctly again!

Firmware update

Besides the replacement fuser was a note: It is required to update the machine to the latest firmware after replacing the fuser unit. As I already did this in one of the first steps when I tried to figure out the reason for the marks, I didn't have to run a firmware update anymore. But as of this writing in January 2021, the newest firmware version is:

Main Firmware Version: ZA
Sub1 Firmware Version: 1.10
Sub2 Firmware Version: Q1811192000

Reset the fuser counter

Now that the fuser was replaced, the printer still thinks the old fuser unit is in the printer. This can be verified by checking the maintenance info page on the printer's IP:

Brother MFC 9330 CDW fuser counter not reset after replacement

Use this procedure to reset the fuser counter:

Touch and hold the "Home" button for around 5 seconds -> 4 rows will be shown
Touch and hold the last row (even though there is probably nothing written in it) -> a number pad will show up
On the numbers pad (not the one in the display) enter the following combination: * 2 8 6 4 -> This will display the maintenance information in the display
On the display, set 8 8 -> this will show the "Reset-Fuser Unit"
Touch the "SET" key on the display, twice
Then touch the "Stop" key on the display
Finally, enter the combination 9 9 on the printer num pad (not in the display) and the printer will restart

I created and shared a video for this:

Add a comment

Show form to leave a comment

Comments (newest first)

Jeremy from wrote on Jan 16th, 2022:

Hey thanks for posting this - I had the exact same issue, same model, living in the same country as you, and this helped me fix it easily! New fuser from digitec and 20m of work, good as new! Cheers!

Duraid from Canada wrote on Nov 15th, 2021:

I have exactly the same problem. I found this video about cleaning the fuser drum. I'll try it first before buying a new one. Thanks a lot for sharing.

https://www.youtube.com/watch?v=uV7N7gmUJnk

ck from Switzerland wrote on Oct 21st, 2021:

Paolo, obviously something went wrong - but you are barking at the wrong tree. According to Brother USA, the Print Unable 05 error comes from a mechanical error. So it might be that the drum unit was not correctly placed. I suggest to either contact Brother support or you comment on the video from Hermes Lara. Good luck!

Paolo from wrote on Oct 21st, 2021:

I followed the instructions on your page and watch the video you show to use by Hermes Lara now my printer keeps saying print unable 05 every time I turn it on and I cannot print. Help what is wrong with your instructions?