Check the following points to resolve the issue:

• If colored lines appear at 1.2 in. (30 mm) intervals, identify the color causing the problem and replace the toner cartridge that matches the color of the line.
  
  To identify the color 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 color causing the problem.
  3. Replace the toner cartridge of the color. Click here to see the details of how to replace the toner cartridge.
• If colored 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.