White Lines (To Sub-Scan Direction) - Konica Minolta bizhub PRO C6501 Troubleshooting Manual

8 White lines (to sub-scan direction)

[Symptom] White lines to sub-scan direction (paper feeding direction)
A: White band appears at the single color,
A-a Charging corona problem
A-b Developing unit problem
A-c Scratched drum
B: Sharp white band appears at the single color, see probable cause B.
B. Foreign material exists in the laser beam path
C: If the sharp white band appears at the single color, see probable cause B.
C-a White line appears regardless of color (Scratch on the transfer belt)
C-b White line appears regardless of color (intermediate transfer belt filming)
A-a: White line appears on single color (charging corona problem)
[Probable causes] Drum potential failure
1) Charging grid gets soiled with the toner etc. and the potential control becomes poor.
2) The drum surface potential increases at the position corresponding to the soiled part of the
grid.
3) After exposure to the drum, the potential does not decrease and white band appears.
[Solution]
1) Clean the charging grid with the Hydrowipe (p/n 65AA-9920) which does not produce lint.
2) Clean the charging wire with the equipped cleaning material.
A-b: White line appears on single color (developing unit)
[Probable cause] Check the toner bristle of the respective color developing unit. If the bristle
is not formed at the specific point, the foreign material is caught at the developer regulating
blade.
[Solution]
Replace the developer and clean the developing unit.
A-c： White line appears on single color (scratched drum)
[Probable causes] The scratch is on the respective color drum.
[Solution]
Paper feeding direction
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