Please check the following points:

• Make sure that you use paper that meets our specifications. A rough surfaced paper or thick print media can cause the problem. To see what kind of paper you can use, click here.
• Make sure that you select the appropriate media type in the printer driver.
• The problem may disappear by itself. Print multiple pages to clear this problem, especially if the printer has not been used for a long time.
• The drum unit may be damaged. Put in a new drum unit. To see how to replace the drum unit, click here.