no sounds output on Sony KDL-40EX720

Do you have Control for HDMI/Bravia Sync (CEC) enabled on your TV? Do you have any other devices connected to your TV? Unplug any devices from your TV before your start the TV Setup process in the Sonos app.

In HDMI Set-up, Control for HDMI is on. I don’t have an enable Bravia Sync option. Yesterday, in the controllable HDMI system list, Sonos Arc was listed. Today when I turned the TV., it said something about a communication failure and disabling/disconnecting something. Since then, No more Sonos Arc in the list of devices.

I did disconnect everything.

When I plug the soundbar in another HDMI plus, it shows a screen saving pattern, the soundbar plays the Sonos radio without issues. I wonder if something is fried in my HDMI arc port...

Control for HDMI is the same as Bravia Sync.

Do you have any other devices connected to your TV?

OK, I noticed something interesting that escaped my attention yesterday: while the Sonos Arc is detected in the device list, it is never on HDMI port 1 (the Arc port). It is detected after I connect it to another HDMI port and when I then change the cable to HDMI 1, it is again detected but under the previous port it was connected to.

I then did a factory reset, reconnected the HDMI cable, I got the message about a sound system being active, still no sound and the device is still listed under HDMI 2 while it is plugged into HDMI 1.

Does this give any clue about what is going on?

No other devices plugged in while I was doing this (except the antenna cable).

What you described is very odd. There might be something wrong with your TV.

Try this:

1. Unplug your TV and Arc from power for about a minute.
2. Plug them both back in and turn on your TV.
3. Set “Speakers” in your TV settings to “Audio System”.
4. Set “Control for HDMI” in your TV settings to “On”.
5. Set “HDMI/DVI Audio Source” in your TV settings to “HDMI Audio”.
6. Run “TV Setup” under the Arc settings in the Sonos app.
7. Follow the instructions in the app and plug the HDMI cable in HDMI 1 on your TV.

If this fails, you may just have to use the HDMI to optical adaptor.

Might not hurt to also check for updates from Sony for the TV set.

The TV has the latest software and the optical cable does not fit in the optical socket of the TV, it won’t get completely inside. Are there different format for optical connections?

@GuitarSuperstar, I did all that and the TV says “no device detected” and the Sonos App says Bravia Sync not connected.

Now I remember I had an issue with my set top box (Optus) after a lightening strike that also fried an ethernet port on another device. I had my set top box replaced thinking it was the box that was fried, and the box worked fine after that (not sure in what port though, that was 5 years ago).

Could it be that the HDMI input of the HDMI ARC port is working but not the HDMI ARC out? In other words, could the ARC functionality be fried while the rest works fine on HDMI 1?

Yes, it is very possible that the lightning strike damaged the HDMI ports of your TV. Were you able to get the optical adaptor connected?