How to reset the memory on an HP Deskjet 3820 printer? -

I have done the usual step of covering up the 4 contacts either side and it still wont work - has anyone got any other ideas please?

Hi kev Remove all the ram. Unplug the printer for 30 seconds. Re-install the ram and power it up. It should display all kinds of commands and then, give you the default display.

un install it and install it again