ЧЗВ и отстраняване на неизправности

Please check the following points:

• Clean the inside of the printer and the primary corona wire in the drum unit.
  To see how to clean the inside of the printer, click here.
  To see how to clean the corona wire of the drum unit, click here.
• The drum unit may be damaged. Put in a new drum unit. To see how to replace the drum unit, click here.