HP all-in-one disable sleep mode and other secret menus

Yes, you CAN actually disable the sleep mode on HP all in one printers, set the rings to answer outside the 2-6 ring range and many other tricks and tweaks. These secret modes and settings are pretty heavily guarded because changing them involves accessing modes that contain settings that may BRICK the unit (render useless).
If you need to modify a specific behavior of an HP inkjet like changing the MAC address of the network card for a specific purpose etc, there's a large number of settings that can be accessed.
Send an email to me ([email protected]) specifying what you need to change and WHY you need to change it, and I will help if there is a way to do it in the machine.
I do charge for this advice, as a preventative measure against consumers posting the information I give out for free.
I also reserve the right to refuse certain services (and would not charge of course in that case) for ethical reasons. For instance, if you want to change a unit's serial number in the firmware, you better have a really good reason for doing it, and I have to believe your reason!