CEC/ARC issues with the Dock and TV with sound bar

[tri]

tl;dr

I was sent here by Steam support, below is my understanding of the bugs and workarounds, please correct me if I'm wrong!

The Deck's GPU does not support CEC features and will cause issues when the TV it is docked to has CEC enabled. After you close a game, external sound (TV or sound bar) will stop working, Steam may lock up while trying to close the game, etc. As a workaround, you can disable CEC (use "ARC only" on the TV), or block the CEC pin (either physically or with a dongle).

I am experiencing this with Valve's dock, and Vizio TV + Vizio soundbar; but I expect this to happen with any third party dock and likely other TVs as I think the issue is within the Deck. I have seen similar posts about JSAUX docks and Sony TVs.

definitions

ARC - An HDMI feature that allows you to feed audio from the TV to an external sound system, such as a sound bar. This way, you can connect something like a Switch or Chromecast to a TV, and have video come through the panel while having audio through the connected soundbar.

CEC - An HDMI feature that allows bidirectional signalling and control between the TV and connected device. For example, if you grab your Joycons to wake your Switch, or press the home button on your Chromecast, it will turn on the connected TV and switch to the corresponding input. The TV inputs will be named according to the device. If you turn off the Switch, it will turn off the TV, if you turn off the TV, it will turn off the Switch.

reproduction steps

1. Connect Vizio TV to Vizio Soundbar via HDMI (ARC) ports
   
2. Enable CEC via TV settings
   
3. Connect Steam Dock to Vizio TV via HDMI port 4
   
4. Connect Steam Dock to Steam Deck via USB cable
   
5. Boot Steam Deck, ensure audio is emitted via Vizio Soundbar through Settings -> Audio -> Speakers (external) // auto will correctly detect this
   
6. Cycle through UI menu and launch a Game to confirm (eg. Cuphead) that Vizio Soundbar is working
   
7. Vizio Soundbar is working as intended
   
8. Exit the game (eg. Cuphead)
   
9. Vizio Soundbar is no longer emitting sound (eg. UI, or game relaunch)
   
10. Switch Vizio TV input to secondary device (eg. Chromecast), play audio (eg. YouTube video), Vizio Soundbar is emitting sound
    
11. Switch Vizio TV input back to Deck, Vizio soundbar does not emit sound again
    
12. Power cycle Steam Deck, test Vizio Soundbar as above, it is working again

workarounds

• Use a CEC blocking HDMI dongle
  
• Change the TV from CEC to ARC only mode
  
• Using the TV's menu, cycle between built-in speakers and the external soundbar, this seems to reset the Deck's awareness of the sound device
  
• Restart the Deck

[prettejohn]

Yep. I had exactly the same issue with the Jsaux dock so eventually sent it back. You can buy a dongle to stop this but was hoping that they would resolve this.
I'm using an LG C9 TV with LG Soundbar.
Anyone solved this??

[tri]

Originally posted by prettejohn:

Yep. I had exactly the same issue with the Jsaux dock so eventually sent it back. You can buy a dongle to stop this but was hoping that they would resolve this.
I'm using an LG C9 TV with LG Soundbar.
Anyone solved this??

Just FYI, I had two other issues:
1) sound randomly and transiently disconnected during gameplay, sometimes just never came back
2) bluetooth controller transiently disconnected, sometimes unbinding Switch Pro remaps

I tried searching both the community forums and Reddit, didn't really find anything helpful. Valve support was no help at all.

What I can say is that switching to the preview branch eventually gave me access to a dock firmware update that fixed both of those issues. I haven't tried testing with the CEC blocker removed since things finally work as expected. It could be worth trying that in case their stable branch still hasn't rolled it out.

Good luck if you give it a shot! Let me know if it works, or if you feel keen and make a separate thread. This experience with Valve was super disappointing, I hope you have a better go at it than I did.