HP printers are generally reliable devices and print high quality documents. Occasionally, you may find that your printed documents have black lines marring the surface of the document. Before you contact your printer's service provider, there are several things that you can try to correct the problem on your own.
Dirty Scanner Glass
If your printer is an all-in-one device or has a lid that lifts, dirt and debris can show up in the final print product as black lines or smudges. This is easy to remedy with glass cleaner and lint-free paper towels or cloths. Be sure to dry the glass completely with a clean, dry, lint-free cloth to avoid spots from the glass cleaner.
Printer Needs Rebooting
Much like computers, printers sometimes begin to function in odd ways if they need to be rebooted. HP recommends that you power your printer on, then remove the cord from the back of the printer itself. You should then unplug the cord from the outlet and wait at least 15 seconds. You can then reassemble the power cord and turn the printer back on.
Print Cartridge Trouble
Many print problems are caused by an almost empty or improperly installed printer cartridge. To begin, you should remove and reinstall the cartridge. If your printed pages still have black lines, try replacing the used cartridge with a full cartridge and print another test page.
Printer Needs Servicing
In rare circumstances, your HP printer may be printing black lines on your printed pages because it requires some other type of service. If you have tried all of the options available to you, contact your service provider and explain what you have already tried to resolve the issue. Many times your service provider will be able to diagnose the trouble for you quickly.