When you change TV volume using the remote, the volume adjustment is carried over HDMI-CEC from the tv to the Arc.

If you turn the tv off, the volume signal can’t be transmitted over HDMI-CEC.

Solution - leave television on when playing music so the remote still controls volume, or programme a remote to work when the tv is off https://support.sonos.com/en-us/article/control-sonos-home-theater-with-your-tv-remote

Hi. Thanks for the reply but I tried it and didn’t help 

Is by chance this Sonos One SL not part of the ‘room’ that the TV is connected to? TV remotes can only control ‘home theater’ room speakers, and not any grouped room speakers. 

Thanks but This isn’t a Sonos 1 sl. I have the Sonos Arc SL sound bar. 

Ah, apologies. My mistake. 
 

To my knowledge, it should work as @Mr. T states. Have you tried to call Sonos Support directly to discuss it?

@dingdong - what television are you using? Maybe someone else will say how it works for them.

I use a cable box remote for volume control, rather than the actual LG tv remote.

Only other pointer I can give is to check the remote is sending an IR signal. Bluetooth I don’t believe will work, but happy to stand corrected as I’ve not really had any issues controlling the volume with tv on/off, so knowledge in this area is a little sparse.

Hi! I did reach out to technical support and they were no help.  He said you cannot use a remote to operate the Arc when playing music.  I know that isn’t true because my friend has the same setup and it works great.  I’ll try to figure out if it’s on IR. 
Thanks so much 

Yes, it’s definitely possible.

My Apple TV 4K remote can control the music volume on my Arc when both the TV and the Apple TV are off.

My remote will not work for music even with the tv on. I have 2cable remotes and a Sony remote that came with the tv. None of them work when playing music from Pandora or Spotify.

When you tried to setup a remote previously, where in the process did it fail? Did you receive any error message?

Do you know the model number of your Sony TV? Are you able to control the tv audio without any problem? Is the Sonos Arc connected to the ARC/eARC port of your tv?

Sony XR75X90J 4K HDR ULTRA..  When setting up the remote it doesn’t do anything. The light on my Arc doesn’t blink.

Hi @dingdong 

Welcome to the Sonos Community!

As the Arc doesn’t react, please try programming your Arc to accept another IR remote for a older device you no longer use - if that works, then you may need to tell your Sony remote to be an IR remote, rather than a Bluetooth (a guess, but it’ll be some kind of radio link) one.

I hope this helps.

Hi.  I finally got through to Sonos and he said I can’t use a remote to control the arc. Only thing I can do is use my phone app and turn it up and down 

That is not correct information you were provided with.

Do you have another remote that works over IR that you can try?

Hi @dingdong 

This only applies to CEC remotes (where the remote’s device sends commands through HDMI). It’s possible a TV could forward these even when off, but it would depend on the TV model/manufacturer.

If you have a remote transmitting IR, and a Sonos device has been programmed to accept it, the volume controls will always work - I just verified this on my Amp.

I think @Mr. T is on the right path - try things with another remote. An old Hi-Fi remote would do, or one for an old TV.

I hope this helps.

I finally got it thanks to you all. I tried several old remotes and none worked. Then as a last resort I tried the remote for the dvd player and it worked.

Thanks

Bob

Mr T you were right. I tried older remotes and finally tried my dvd player remote and it works perfectly.

Thanks

Bob