Question : Problem: laser copier making thunking noise as it prints

I have a canon pc 770 laser copier that started making a thunking/ thumping sound when it prints. It is an older unit and i was wondering if it could be repaired and what it might be. I suspect the drum but i am unsure. If I knew exactly what it might be , I could probably repair it. It is printing fine, just making that noise and it seems to be getting worse.

Answer : Problem: laser copier making thunking noise as it prints

If it is printing fine I doubt it is a bad gear...

If you have a laer printer that has both a toner cartridge and a drum cartridge it may be that the waste system is backed up in the drum...

Take out the toner cartridge see if on the end facing outwards (the end you pull out first ) if their is a clear box filled with toner or a trap door looking thing if so this is a waste sump open the trap door and dump out the waste....

If not continue with these instructions

Hold the toner cartridge over a garbage can, bang on the top of it with your fist about 10 - 20 times then on the opposite end (the end that goes into the printer first) their is a cluster of gears.... turn the gear that turns inside of the toner cartridge but does not turn the roller that the toner is attached to usually a very small gear by itself and / or located in the center.


after you have done this remove the drum cartridge... make sure not to touch the drum itself (the shiny part).... hold it over a garbage can. look on the end that you pulled out first their may be a tube with a sliding little trap door on the end. You will need to hold this open while you do the next procedure if not then just continue on....

On the side that goes in first into the machine their should be a gear there turn this gear it may be hard to turn if it is this is most likely your problem... the auger inside the cartridge that wipes off the waste toner is seized.... keep working at it until it loosens up some turning it both clockwise and counter clockwise if it will only turn one direction then keep turning that direction till it eases up. Should not be free spinning but should not be so hard to turn that you almost need pliers to turn it.

If this does not fix it or you can not get that gear to loosen up on the drum cartridge then try to replace the drum cartridge... being that it is printing fine but making this noise it sounds like the gear is skipping because it is seized... it still will print fine for awile but will eventually result in access toner on your pages, black streaks and finally a new drum.