1. Check that the printer is turned on and properly connected to the computer.

2. Ensure that the image drum is correctly installed, making sure that it is correctly seated and in the correct orientation.

3. Try restarting the printer by turning it off for several seconds and then turning it back on.

4. Clean the inside of the printer thoroughly, especially the drum unit.

5. Check whether any printer software needs to be reinstalled or updated.

6. If available, check the printer manufacturer’s website for firmware or software updates.

7. Try resetting the printer to its factory default settings.

8. Consider replacing the drum unit if all else fails.