Please check the following points to solve the problem:

1. The drum unit or toner cartridges may not be installed correctly. Re-install the drum unit and toner cartridges.
   
   
   • Click here to see the details of how to install the drum unit.
   • Click here to see the details of how to install the toner cartridges.
   
   
2. The drum unit may be stained. Clean the drum unit as follows:
   
   
   1. Click here to print the chart. [345KB/ PDF]
   2. Compare your printed document with the printed chart to identify the color of the drum unit causing the problem.
   3. Clean the drum unit of the color. Click here to see the details of how to clean the drum unit.
   
   
3. Make sure that the media type settings in the printer driver matches the type of paper you are using. We recommend trying to change Thick Paper or Thicker Paper mode in the printer driver.
   
   
4. Check the machine's environment. Conditions such as high humidity can cause white spots or hollow print.
   Temperature: 10ºC to 32.5ºC (50ºF to 90.5ºF)
   Humidity: 20% to 80% (without condensation)