Greyish marbeling on printed page & yellow wash allover page.

do a permanent storage init reset

after you have printed a few pages switch the machine off just as the paper leaves the fuser. then open the front cover and take a close look at the image transfer belt ( black plastic conveyor type belt)
use a torch shone accross the belt to better light the error- if you can see these Green/yellow/cyan lines on the belt then theres a good chance its coming from the toner units- ( also try print quality troubleshooting pages in the menus under diagnostics.look at the individual colour pages and look for any lines or Uneveness about the shaded colour) replace whichever toner is not printing correctly

clean the scanner & calibrate the printer thre times ur problem will be resolved

If you have BLACK Marks on the paper the YELLOW roller does not need to be cleaned usually.

To clean the yellow toner off the roller use a DRY lint free cloth. For this issue my suggestion for a resolution to the Yellow toner issue is replace the toner. They are not supposed to leak in the first place.

As for the BLACK tone on the left of the page you most likely have a Fuser issue causing that.

Are you using a factory new HP cartridge? If so, contact HP and request a warranty replacement of the toner cartridge.

Generally this is a toner cartridge issue. Are you using genuine toner cartridges or generic remanufactured? I have attended alot of repairs on this model when clients use generic cartridges. Usually a genuine cartridge fixes the problem.

Hello sir; Try to clean out scanner mirrow, see what happen!

just reset the printer to factory settings , use the menu to find factory settings .

Are you sure that none of the other colours are empty? If they are then this could be the problem

try to locate the print head of the unit. you will see a mirror there. clean the mirror maybe it has some foreign object.