Description: Printed horizontal black lines

Possible Reasons:
- Excessive resistance in the charging roller, indentations, scratches, or OPC contamination lines can all cause horizontal black lines in printing. The specific cycle of the consumable can be determined by the spacing of the white lines (refer to the defect cycle table).
- Generally, horizontal black lines in printouts are related to the drum and have little to do with the printer itself.
Process 1: The problem stopped after replacing the new toner cartridge
Toner cartridge defected.
Process 2: The problem still exsits after replacing the new toner cartridge
Printer problem/batch complaints identification