When your printer's quality begins to diminish, there are ways to clean it up and help improve the printer's function. The cleaning brush from HP is recommended for use each time you change your toner cartridge. There is also a downloadable cleaning utility offered by Hewlett Packard -- designed for the Laserjet 5 and 6 Series printers.
Purchase a cleaning brush designed for HP printers.
Turn off the printer and unplug the power supply. Open the top of the printer and use the cleaning brush to carefully remove dust. Replace the top cover, plug the printer in, and turn it on.
Find the HP Laserjet Cleaning Utility CD that came with your printer. You also can download the file from the HP support website into a temporary directory -- link provided in References section below.
Run the file "Hppclean.exe." Follow the instructions on your computer screen.