i have a wired home network and two series 3 units. one HD, one premiere. the HD unit has stopped seeing the network. no changes here in connections. the Premiere is working fine with the network and my computers also working fine. how can i diagnose where the problem is? is there onboard diagnostics? i have unplugged cable and tivo. no change. the message is no dhcp connection. i tried letting the unit assign an ip address also with no luck. the unit works fine otherwise. it says there is no network connection. not good with the new tv season just starting. this unit is about 4 years old.