Check the following points to solve the problem:

1. To get the best print quality, we suggest using the recommended paper. Check that you are using paper that meets our specifications. Click here to see details of the recommended paper.
   
   
2. The drum units or toner cartridges may not be installed correctly. Check that the drum units or toner cartridges are installed correctly.
   
   
   • Click here to see how to install the drum unit.
   • Click here to see how to install the toner cartridges.
   
   
3. Perform the calibration. Click here to see how to carry out calibration.
   
   
4. Make sure toner save mode is off in the control panel or the printer driver.Click here to see how to change the toner save mode setting.
   
   
5. Make sure that the media type setting in the printer driver matches the type of paper you are using.
   
   
6. The toner may be solidified inside the toner cartridge. Take out all the toner cartridge and drum unit assemblies and then shake all four toner cartridges gently.
   
   
7. Wipe the windows of all four LED heads with a dry lint free soft cloth.Click here to see how to clean the LED head.