You wont see a light on the ethernet port on the miner itself, but yea the Raspi itself should be showing some kind of connectivity. Could be a bad cable. Could be a bad cable. Try another cable directly into the Raspi itself (open up the case). It is possible the Raspi ethernet port itself is bad. Alternately plugin and HDMI cable into the raspi and hook it up to a monitor. Post the output if there are errors. Might be able to help you out better if I see whats going on under the hood.