Brother MFC-9335CDW smudging paper

First thing I check on all of these split drum systems (Lexmark, Ricoh and commercial Canons with the drum/dev split from the toner) is a halfway test. Run the same document but make sure it DOESN'T hit the fuser - if the defect stops there, it's the drum. Being a color machine, you probably want to do this with isolated text samples snd see where it smudges as Brother has dedicated CMYK drum units on these, rather then the single drum they moved to on later generations (yet refuses to sell individuals like Lexmark does with their commercial printers that sit on a office floor, while the desktop units have a single combo drum but an option to buy a CMYK or K drum so if your color devs are fine, you replace the bad K dev). If the defect isn't there, you have a bad fuser.

The problem with these is that the fuser is a royal pain to replace :-(. Brother used to build them where the fuser was accessible from the top (yeah, even the MFPs), but they moved away from that to make the units more compact. These were all early color units with lower lifetime parts, such as 25- 50k page drum units and 70- 75k page ITBs, which required periodic replacement. As a result, you had to swap components more often, but it was manageable. Brother ditched the easily replaceable fuser for compactness later on, but provided us with 100k-page transfer belts and eliminated some of the nonsense about stopping the printers - now, short of toner, they yell at you. Oh, and the lasers were always a wear item on early color lasers from Brother, every 100,000 pages. We would just reset them and wait until they went out of spec, because that was borderline penny-pinching.

Anyway, here's the SM: https://www.laserexpressinc.com/manuals/...

Make 4 solid test sheets with big gaps so you can catch it with these color codes

• #00FFFF (Cyan)
• #FF00FF (Magenta)
• #FFFF00 (Yellow)
• #000000 (Black)

Gap these SIGNIFICANTLY so you can catch the bad drum. Maybe make 2 sheets with 2 colors each. This doesn't eliminate the halfway test, but it makes isolation much easier.