First, unplug and reseat any Ethernet cables in the path from the devices to switches and/or routers. If that doesn't help, replace the cables. If that doesn't help, start debugging the upstream devices (such as the base station).
I had a similar set of symptoms recently. The TiVo couldn't connect to services, HD menus were impossible to use (blue wheel of death), NetFlix couldn't stream, etc. I tried using the TV's own NetFlix app, but it also couldn't connect.
The TV and TiVo are connected via Ethernet to a switch, which then connects to my router in the garage. Since both devices were affected, I swapped the cable that connects the switch's uplink to the router.