In you forgot or brought a printer with a password already set in it and you need to modify settings on it, the only way to access the printer configuration page is to do a COLD RESET of the printer. You can initial the process by holding the “GO” key while powering up the printer. Once it finished powering up, you should be able to access your printer by telnet or the web to make any configuration changes.
If holding the “GO” doesn’t reset the password, you might need to do a reset of the NVRAM.
e.g. For an NVRAM init on an HP8150
– Power on printer while holding down the “Select” and “Cancel Job” buttons
– If display is blank and lights on, release holding.
– You should see on the display NVRAM INIT.