You are certainly right that it shouldn’t be like that and I don’t think it usually is.  I have an Arc connected to an LG TV and have had no issues.  No comfort to you, I know, but just to point out that your experience is not common.

What is the current state of play with the Ones?  Are they working OK?

The ones work fine, but not using them with the TV. 

Only one connected to the TV (or atleast tried to be connected) is the Arc. I’ve exhausted all the options, probably need to sell the soundbar. 

Had a nice afternoon trying to set it up again, it does not work. It does not connect to the TV. I’ve tried all of the settings. The app just keeps saying: “Use your remote to connect the tv speakers” or something similar.

A guy asked what’s my network like. I don’t understand how has that got to do anything with my speaker not connecting with my TV, since all the devices find eachother fine. The arc works for playing music, so it’s not a network issue. 

I had somehow concluded the Arc wasn’t a problem anymore. So your problem is that the Arc does not connect to your LG TV? Is HDMI-CEC (Simplink) turned on in your TV settings? Have you tried contacting Sonos?

Yes, it does not connect to the tv :(

Simplink is turned on, yes. Have tried contacting Sonos, send them the troubleshoot thing and no response so far.

Hi @tiltedbeyondbelief, you mentioned in your original post that you had to disconnect other HDMI devices in order to get the Arc to connect to the TV - what other HDMI devices do you have connected?

It’s possible that one of the other devices connected to the TV is interfering with the CEC communication, and blocking Sonos from connecting to the TV - it may be worth disconnecting all other HDMI devices, and reconnecting them one at a time to see if a particular device is causing issues.

As an experiment, for the purposes of troubleshooting, would you be able to connect the Arc using optical out and the adapter?

Last time I tried connecting Arc, I fully disconnected everything else. I just have a TV box connected and it did interfere with the connection, but after I disconnected it, the arc would connect, but it just doesn’t connect to the LG tv anymore. With or without the other HDMI’s in. Tried the optical cable, doesn’t work with that as well. 

I bought the CEC less adapter for my TV box cable, so it wouldn’t interfere, but now Arc doesn’t connect at all. 

1. I got the Arc connected in december, it worked well but every time I turned off the TV, I had to take other HDMI out and reconnect Arc via the app. 
2. Bought CEC less adapter for the other HDMI cable so it doesn’t interfere. 
3. Took 2 weeks to arrive and now Arc just doesn’t connect to the TV at all. Tried all of the settings, different HDMI ARC positions, optical cable. It just says: “Use your remote to connect TV speakers” or something like that, nothing else. 

Hi. Could you explain what you mean by ‘different HDMI-ARC positions?  Most TVs have only one HDMI-ARC connection.

I am also puzzled by the message “Use your remote to connect TV speakers”.  Where did this appear? It doesn’t sound like something that would appear in the Sonos app.

As the Ones are OK, I would suggest you factory reset the Arc only.  Then in the S2 app go into Settings, System and select ‘Add Product’.  Follow the on-screen prompts.

To factory reset:

https://support.sonos.com/s/article/1096?language=en_US

Use the ‘join’ button on the Arc for the reset.

Factory reset it 3 times. 

“Use your TV remote to turn on TV Speakers in Sound Settings.” - this is the exact message I get in the Sonos app. Have tried all the settings in the TV’s sound settings.

Sorry, made an oopsie about the different HDMI-ARC positions. It’s always been in the “ARC” HDMI port.

Sorry it's still not working for  you. I think your only option now (apart from sending it back for a refund) is to call Sonos' telephone support. They can remote access your system and take a look.  If there is a fault with your Arc they should be able to tell.

I hope you find a solution.