Check the following points to resolve the issue:

• If coloured lines appear at 1.2 in. (30 mm) intervals, identify the colour causing the problem and replace the toner cartridge that matches the colour of the line.
  
  To identify the colour of the toner cartridge and replace the toner cartridge, follow the steps below:
  1. Click here to print the chart. [345KB/ PDF]
  2. Compare your printed document with the printed chart to identify the colour causing the problem.
  3. Replace the toner cartridge of the colour. Click here to see the details of how to replace the toner cartridge.
• If coloured lines appear at 3.7 in. (94 mm) intervals, install a new drum unit. Click here to see the details of how to replace the drum unit.