The Background Is Generally Dark

Troubleshoot by checking in the following order:

Are White Areas Generally Dark When Copying?

Adjusting the density of the background may solve the problem.

[Home] screen on the control

[Copy]

[Density]

[Adjust Background Density]

[Adjust (Manual)]

adjust the background density.

* Parts other than the background may also be affected depending on the color of the original.

Are You Using the Machine in an Appropriate Environment?

Re-install the machine in an appropriate environment.
Moving the Machine

Keep the toner cartridge in a suitable location and try printing again after 2-3 hours. If the problem persists, replace the toner cartridge.
Replacing the Toner Cartridge