Showing results for 
Show  only  | Search instead for 
Did you mean: 

MF634CDW - Color Image Class Laser Printer Problems


Trying to troubleshoot this laser printer.  The blue color drips dots now on all printed materials.  Already did the two types of cleanings:  Clean Fixing Assembly amd Clean Feeder.  Clean ITB button refuses to start, so we are unable to get that going.  Does ceylon blue tomer cartridge need changing periodically?  It is leaving crumbly blue bits all over inside the machine now after the two cleans.  Tried to remove the 3 cartridges and leave black inside only, but there must be a sensor telling the printer not to function due to the 3 missing cartridges.  And naturally, the 3 years warranty just expired.  Thanks in advance.



You mean CYAN cartridge, not "Ceylon", right?

Is this a genuine Canon cartridge, or is it an aftermarket (non-Canon) cartridge?

Sorry, iPad typing at its finest.  Yes, CYAN.  It’s blue and leaving powder bits all over the paper being printed, polka dots and inside the laser printer itself.  Any idea why this is happening and what troubleshooting I can do that I haven’t tried already?  TIA.

PS. And yes, it is a genuine Canon cartridge.

Product Expert
Product Expert

Hello Majag,

The issue you are describing would usually mean the toner is not seated properly or it is damaged and leaking. You can try removing all of the toner cartridges and checking the inside of the printer for any loose toner powder that you can wipe up with a damp cloth or you can try replacing the cyan cartridge to see if it resolves the issue.

If it continues to have issues, it would mean the printer needs service. You can log into your MyCanon account to view any available service options.

Thank you for your suggestions!


It sounds like you have a leaky cartridge that toner is just falling out of. 

Compare it to one of the other cartridges to see if it looks different in the area where toner comes out. Something ajar, broken, loose.....

Thanks for your help!