Bizhub 754e recurring lines in drums

[frd909]

A 754e I am servicing has repeated failures of drum units (OEM DR711K). The first was changed out due to it reaching its life. After that, the one changed only got a few thousand prints before a permanent line etched itself into the drum. Thinking it was possibly a defective part, it was changed out and the next drum got 100k prints or so and then that drum got permanent lines as well. After cleaning the imaging area as best as possible, another drum was installed and this one only got a few thousand again and got permanent lines in it. I can't seem to figure out what is causing it.

Any ideas?

[davidmtupper]

Do the lines appear in the same location each time? If so what in the copier lines up with that location. If not something may be happening with the dev unit, intermittent toner rocks or something similar.

[tulintron]

Do these lines appear on the same part of the drum? In which part?
Does this line also exist on the transfer belt?


Any photo?

[blackcat4866]

Do the lines appear in the same location each time? If so what in the copier lines up with that location. If not something may be happening with the dev unit, intermittent toner rocks or something similar.

+1 on developer rocks, or some other foreign matter wedged under the doctor blade. If you wipe the developer aside, you should see a distinct wear mark on the developing roller that matches up to your drum wear marks. =^..^=

[copyman]

Are you replacing the complete drum unit or just the aftermarket drum, blade, etc? If just the aftermarket items to rebuild drum unit then I would try new complete OEM unit.

If drum unit is OEM and line is scored into drum at same place every time should be very easy to troubleshoot. Drum not sitting on dev unit properly, or bad developer unit. Only thing that is "suppose" to contact drum is drum cleaning blade & developer brush on mag roller.

[Todd Glenn]

Did you change the developer unit on schedule? The positioning rollers/spacers (plastic and on either side of the drum) ,wear down in time,
allowing drum to contact mag roller.