Laserjets 5P, 6P, 2100, 2200 and other printers that do not have a display panel (LEDs only).
These models are designed as low volume personal printers and do not have a maintenance count that needs to be reset or a readily accessible service mode. You can cold reset these printers or completely reinitialize the NVRAM (nonvolatile ram) to factory defaults. Cold resetting will reset most of the system parameters to factory defaults and reinitializing the NVRAM will reset ALL system parameters to the factory defaults. Also, there is a service mode for these printers but it is only accessible through software using PJL service mode commands. Buy the printer's service manual if you want to learn more.
HP Laserjet 5L, 6L, 1100, 1200 do not have a service mode. You can only perform a cold-reset and continuous self-test.
Multifunction printers - printers/copiers/fax/scanners (e.g. HP 3100, 3150, 3200, etc.)
Service modes in these printers are more extensive because of the scanning and faxing features. We recommend buying the service manual for these units if you will be doing any repairs beyond mechanical components.
Laserjets 5P, 6P, 2100, 2200 and other printers
