I have an HP 3330 MFP. Yesterday, I changed the toner cartridge and put in a new C7115X (HP branded...) cartridge.
When I made a copy on it, dark horizontal bars with a lot of loose toner bits were present. Same thing when printing... The bars are about 1.5" apart (7 heavy ones per page). I ran about 15 pages through with no change so I figured the new cartridge was a dud. Put in my 2nd spare cartridge ... and it had the exact same problem!
I looked in the manual and found how to clean the printer media path (From the service menu, choose "Cleaning Mode"). That didn't make any change at all.
The thing I don't understand is how it could go from working fine with an empty cartridge to printing horizaontal bars in two brand new HP cartridges.
Any ideas on how to fix this?
Thanks very much,