That would require me to have a note with the generated password around otherwise you can only reset it in a state inaccessible for everyone. Or the manufacture

That would require me to have a note with the generated password around otherwise you can only reset it in a state inaccessible for everyone. Or the manufacturer has a db with all serial number and pwd combination, which remains a security issue. You could as well force the user to set a password for the device to work and a way to reset to factory default. But this would probably now be against the law.