Dell C1760nw "bricked": no print, no operator panel response, no usb or network connection

Printer status button is green, LCD screen show ready to print however the printer is unresponsive. The operator panel accepts only a couple of clicks then stops responding. I have tried to get access to the settings through the network interface or the toolbox (usb) but I am unable to do it. NIC lights are off even though the ethernet cable is connected (cable and router port were proved with a laptop). If I connect the printer to a computer using usb, network cable removed, Printer Tool Box returns "Failed to acquire the information" and printer status Power Off, windows shows the printer online.
I believe printer needs to be reset to factory settings, question is how if nothing seems to response.