I would look at your TV settings to make sure it’s sending audio through the headphone port.  Sonos will show it as disconnected if nothing is coming through. 

Also, know that the line in port on the Era speakers are not designed for TV use.  The audio is intentionally delayed in order to buffer for multiroom audio, so it will not be in lip sync with the TV.  Some people are bothered by this, others are not.

Thanks Danny, the TV is definitely out putting audio through the headphone port is it still works fine when connected to the line in-port of an old Bose wave radio I was using for TV sound and may still have to by the looks of things, a bit misleading calling it line-in functionality and mentioning that it can be used with turntables & cassette / music players. Any other ideas ?

You’ve probably checked that everything is wired correctly, so probably not that. Different wires perhaps?  I’m not aware of any setting on Sonos you could be missing. Maybe reboot (unplug for a few seconds) the Era speaker?  I guess the next thing I would try, if I have another audio source  with line out, like a second TV, is connect to that and see if you get audio.

Another thing...maybe give bluetooth connection a try if your TV can output in bluetooth.  I have that setup with my Era 300s and don’t really see a big lip sync issue like I was expected.  It’s not a setup I would use for ‘serious’ TV watching, but seems fine casual watching every now and then.

Hi Danny just a quick update, I should have mentioned that the adaptor I was using was NOT one supplied by Sonos as they did not have any where i purchased the Era 100 from so i sourced one locally 

I have since got the adaptor directly from Sonos and hey presto is if by magic it works fine so just a word of advice for any other users who may have experienced the same issue, you can't use standard USB C to headphone 3.5mm socket and expect it to work. The Sonos one must be wired differently.

Issue now solved

Obviously a headphone adapter will not work. The data goes “the wrong way”. You need analog to digital, a headphone adapter is digital to analog. Its not “wired differently”, it is an utterly different device.

ik heb hetzelfde probleem, sonos app geeft aan “lijningang losgekoppeld” met niet origineel kabeltje.

weet iemand waar je op korte termijn het Sonos kabeltje kunt bestellen, lijkt nl moeilijk leverbaar?

From Google Translate:

U kunt een combo-adapter aanschaffen, die de Line-In en Ethernet omvat.

@pd1bw Je vindt het Nederlandstalige forum hier: https://nl.community.sonos.com