Horizontal black lines across page.
Horizontal lines usually indicate a toner cartridge that is not cleaning properly.
A. If the distance between defects is 38 mm (1.5 inches), 47 mm (1.85 inches), or 94 mm (3.7 inches), the print cartridge might need to be replaced.
B. Clean the printer.
1. Clean the inside of the printer and run a cleaning page to clean the fuser.
Over time, particles of toner and paper accumulate inside the printer. This can cause print-quality problems during printing. Cleaning the printer eliminates or reduces these problems.
To clean the inside of the printer
1. Turn the printer off and unplug the power cord.
2. Open the top cover.
3. Remove the print cartridge.
4. With a dry, lint-free cloth, wipe any residue from the paper path area and the print cartridge
5. Reinstall the print cartridge and close the top cover.
6. Plug in the power cable and turn the printer on.
Cleaning the fuser:
Run the printer cleaning page to keep the fuser free of toner and paper particles that can sometimes accumulate. Accumulation of toner and particles can cause specks to appear on the front or back side of your print jobs. To ensure optimum print quality, HP recommends that you use the cleaning page every time that you
replace the print cartridge or on an automatic interval that you can set up. The cleaning procedure takes about 2.5 minutes to complete. A CLEANING message appears on the printer control panel display while the cleaning is taking place.
To run the cleaning page:
In order for the cleaning page to work correctly, print the page on copier-grade paper (not bond, heavy, or rough paper).
1. If your printer model includes a duplexer, open the rear output bin.
2. Press Menu to open the menus.
3. Use (Up button) or (Down button) to scroll to CONFIGURE DEVICE, and then press (Select button).
4. Use (Up button) or (Down button) to scroll to PRINT QUALITY, and then press (Select button).
5. Use (Up button) or (Down button) to scroll to CREATE CLEANING PAGE, and then press (Select button).
6. Follow the instructions on the cleaning page to complete the cleaning process.
7. If your printer model includes a duplexer, close the rear output bin.
If this helps resolve the problem, please post a reply. Binary Bob