HP Color Laserjet CM3530 Grey Shading on whole page
See the attached file showing the shaded background that covers the entire page. At first I thought it was a bad toner cartridge so I replaced it with a new one. That didn't fix the problem so the next thing I tried was to put one of the other color toners (I tried yellow) in the black toner slot and the black in the yellow slot. This time the background shading was yellow instead of black.
It seem that whatever cartridge is in the black slot produces the shaded background. Anyone have any suggestion as to what this might be?
Thanks for any help