The density of the print varies down the page. Lighter areas in horizontal bands or horizontal stripes can be seen on a letter or A4 page with the leading edge being the short side (short edge fed).
Touch the Status/Supplies icon in the printer control panel. Check the supply status and replace those that are low or empty.
Proceed with the next step if all supplies register sufficient amounts.
Print the Print Quality Samples. From the control panel, navigate through: Settings > Report > Print Quality Pages. Check to see if the issue persists. If so, proceed to step 3.
Enter the settings menu: Print > Quality > Advanced Imaging > Color Adjust > Start, and print a test page. Check to see if the issue persists.
Note: Color Adjust can be performed at the control panel or the embedded web server (EWS).
If the issue persists, remove and reinstall the imaging unit. To do so, see Replacing the color imaging kit, or perform the following steps:
Open Door B.
Remove the waste toner bottle (WTB).
Unplug the green cable.
Remove the imaging kit. Pull the unit out of the device and set on flat surface.
Reinstall the imaging kit and plug in the green cable.
Insert the waste toner bottle then close Door A and Door B.
Perform a test print and check if the issue persists.
Stop seeing random dark or light areas on your prints. Here is a solution.
Do horizontal dark lines appear randomly in your prints? Check the paper settings from the Printing Preferences or Print dialog.