Hello,
I have a LaserJet CM1312 nfi MFP and it has recently started printing all the pages with lines of color across them.
I'm not sure if this has anything to do with it, but the unit tends to calibrate a lot - A minimum of once a day, but my wife notices at least 4 times everyday.
I have attached copies of the HP Test page so that you can see exactly what the printer quality is like.
When I print off a black and white document, you can see that the text is mostly fine, underneath the lines of color.
I'm hoping someone can help me out, as I'm at a loss!