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Answered

LG+Arc Ultra=grrrrrrr!

  • April 30, 2025
  • 11 replies
  • 564 views
D

Hi there, a really annoying problem: Got my Arc Ultra set up, eArc to HDMI, 2 Era 300 as rears and planning on buying a Sub 4 once the pain in my purse goes away.

There are 2 content suppliers connected to the TV, an LG OLED65CS9LA: an Apple TV (latest model) and a PS5. Problem is with BOTH of those so it’s either the TV or the Arc. 

  • What happens is that after it was off for a few hours - like over the night - the system will only put out Stereo PCM. I have to manually change the sound mode in the TV settings (anything will work as long as I change it, auto, passthrough, no matter). All the other settings are correct, it’s just as if, when off for a few hours, the TV forgets to tell the Arc that it sends surround sound & me changing stuff will remind it.

I read that it might be a problem with cheapo HDMI cables so I bought an expensive one and a super expensive one and nothing changed.

I am very annoyed and would be extremely grateful for a solution.

Best answer by dancress

I just factory reset the TV. Reluctantly because good settings and all.

 

Let’s see if it was worth it.

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11 replies

Airgetlam
  • Airgetlam
  • 44829 replies
  • April 30, 2025

Sounds more like an issue with the TV and its built in CEC programming to me. Have you checked the TV for software updates? Have you forced the TV to reboot, by unplugging it from the wall for two minutes, then plugging it back in?

If you have, I would recommend that you submit a system diagnostic within 10 minutes of experiencing this problem, and call Sonos Support to discuss it. Don’t post the resulting diagnostic number here, they get sensitive about GDPR.

There may be information included in the diagnostic that will help Sonos pinpoint the issue and help you find a solution.

When you speak directly to the Support staff, they have tools at their disposal that will allow them to give you advice specific to your network and Sonos system.

Bruce
R
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  • Rhonny
  • Prodigy II
  • 2607 replies
  • April 30, 2025

​@dancress 

Is your content actually in surround (eg 5.1 or Atmos)? The Arc will only output what goes into it. Most shows broadcast in Stereo PCM, with surround most common with streaming services. 

106rallye
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  • 106rallye
  • 6600 replies
  • May 1, 2025

Is the TV really off, or just on stand by?

C
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  • craigski
  • Local Superstar
  • 906 replies
  • May 1, 2025

 

D
  • dancress
  • Author
  • Contributor I
  • 5 replies
  • May 2, 2025

Hm. There was an update to the TV including a full reboot and the problem seems to be gone by now. Thanks for your answers!

D
  • dancress
  • Author
  • Contributor I
  • 5 replies
  • May 12, 2025

Update: it’s back. It works ONE time after rebooting the whole system, then the problem is back. Any of you pros got an idea?

Airgetlam
  • Airgetlam
  • 44829 replies
  • May 13, 2025

What did Sonos support say, when you called in? 

Bruce
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  • dancress
  • Author
  • Contributor I
  • 5 replies
  • May 15, 2025

What customer service usually says: ‘it’s the other guys’ thing’ aka the TV. Which is exactly the answer I was expecting & why I rather asked here.

 

Moderator Note: Modified in accordance with the Community Code of Conduct.

bockersjv
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  • bockersjv
  • Local Superstar
  • 2638 replies
  • May 15, 2025

I have the same setup with an LG C4 and not had a problem with this. I have the TV Digital sound output as Auto/Pass Through, SIMPLINK on and apply settings to all inputs.HDMI input as Bitstream and eARC support on. I am also using the supplied Sonos HDMI cable.

Works faultlessly.

D
  • dancress
  • Author
  • Contributor I
  • 5 replies
  • Answer
  • May 15, 2025

I just factory reset the TV. Reluctantly because good settings and all.

 

Let’s see if it was worth it.

D
  • dancress
  • Author
  • Contributor I
  • 5 replies
  • May 19, 2025

Resetting the TV to factory settings did it. Working w/o a fault now.

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