123.hp.com/envy7855. 123hp.info simply assist customers to Setup, Install and Troubleshoot HP Envy model Printers. Un pack the 123.hp.com/envy7855 printer from its packaging and keep the power cords ready to connect in its respective places. Now, place the cords firmly into the wall sockets so that there are no loose connections or any power issues with the devices. After connecting the cords, press the Home button on the left-hand corner of the printer.