BeoSystem 3 MK1: No Sound via S/PDIF AV5 with LG TV

[Alexey Malyugin]

Hello, dear community! I need help with my BeoSystem 3 MK1 (Type No. 9604, Serial No. 20953799).

Setup:

LG 55QNED80T6A (2024)- HDMI ARC/Toslink – coaxial (Tubon 002) –  AV5 SPDIF IN BS3.

Output: 2× BeoLab 8000 (PL1/PL2 Left/Right Front) – bought them for their incredible beauty, but sound only works via RCA.

Video: DVI-OUT BS3 – monitor.

I have a screenshot from the monitor available

V.OPT 2, BS3 test tones work (speakers green).

Attempts:

Settings: Connections → Sound Input = SPDIF (AV5/AV6), Video = HDMI-A, STORE.

Sources: LG (PCM 48/16), PC (Realtek S/PDIF, 44.1/48 kHz) → coaxial/AV5/AV6.

Converters: ARC extractor, PALMEXX (optical→coax), BSP CA-50 (Coax OUT).

Workaround: LG Toslink → BSP CA-50 → RCA → BeoLab (LINE) — sound works.

Tried V.OPT 1/0, but switching doesn’t work (only 2 available).

Issue: No external sound via AV5 (speakers orange), though Sound System shows PCM 2.0. In monitor settings, AV4, AV5, AV6 are not visible. Service menu: IIC1 -84: ACK_MIS, errors 00F8. AV5 is visible in Connections but not activated. Video works stably. I have a screenshot from the monitor available.

Questions: How to activate AV5 for sound? Is an audio-only mode (V.OPT 0) possible? Need advice on settings or diagnostics. I can share the monitor screenshot if needed. Thank you!

 

• This topic was modified 1 day, 17 hours ago by Alexey Malyugin.

[Tignum]

Hello Alexey,

I also have an LG TV connected, a C9 55″, to a BS3 (mk3).

I use a super simple optical (toslink) to coax converter. All works fine, feeding 6 Beolabs through Powerlink.

Do you have Powerlink to RCA cables for the Beolab 8000s then? And you say that the Beolabs show orange leds? Orange leds are not usual and indicate an issue – they should be red (off) or green (on). Do you have Beolabs that work with Powerlink to try? Could it be that the volume coming from the BS3 is too low to trigger the RCA fed Beolabs?

There are some more threads around this, including screenshots of the LG sound output options and the BS3 input options, such as this one: https://archivedforum2.beoworld.org/forums/p/43717/316931.aspx, hope they help to isolate and fix the issue.

Regards,

Johan

Location: Netherlands
My B&O Icons:

[Alexey Malyugin]

Thank you for the response and the link, I’ve read it all. However, this doesn’t quite fit my case. I still want to use BS3 to pass digital audio to BeoLab 8000. I connected via RCA like this: TOSLINK from LG to a DAC → RCA to BeoLab 8000 (Line mode), and it works perfectly.

BeoSystem 3 is glowing orange. BeoLab always shows red. Powerlink is available, and that’s how I’d like to connect.

From the options I tried:

1. HDMI Extractor – HDMI eARC/ARC to extractor → Coaxial to SPDIF on BS3. No sound.
2. TOSLINK-to-COAXIAL converter – No sound.
3. DAC (with TOSLINK-to-COAXIAL function) – No sound.

I suspect I might be mistaken with the settings or modes.

It also worries me that AV4-AV6 are not listed in Monitor Information, even though I’m connecting to AV5-AV6.

Attachments:

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[Alexey Malyugin]

Tignum wrote:

Hello Alexey,

I also have an LG TV connected, a C9 55″, to a BS3 (mk3).

I use a super simple optical (toslink) to coax converter. All works fine, feeding 6 Beolabs through Powerlink.

Do you have Powerlink to RCA cables for the Beolab 8000s then? And you say that the Beolabs show orange leds? Orange leds are not usual and indicate an issue – they should be red (off) or green (on). Do you have Beolabs that work with Powerlink to try? Could it be that the volume coming from the BS3 is too low to trigger the RCA fed Beolabs?

There are some more threads around this, including screenshots of the LG sound output options and the BS3 input options, such as this one: https://archivedforum2.beoworld.org/forums/p/43717/316931.aspx, hope they help to isolate and fix the issue.

Regards,

Johan

Do you have an MK1? Which SPDIF input are you using? How does A.OPT/V.OPT work? In LG, do you select Dolby Digital and PCM?

[Tignum]

Hi, mine is Mk3.

I am using the AV2 S/PDIF sound input on the BS3 (under CONNECTIONS)

The sound out setting of the LG is ‘optical out’ and ‘passthrough’

My BS3 is in V.OPT 2

Have you assigned speaker types and roles? (under SOUND SETUP)?

And ‘default video speaker’ (under SOUND ADJUSTMENT)?

J.

 

Location: Netherlands
My B&O Icons:

[Alexey Malyugin]

 

Tignum wrote:

Hi, mine is Mk3.

I am using the AV2 S/PDIF sound input on the BS3 (under CONNECTIONS)

The sound out setting of the LG is ‘optical out’ and ‘passthrough’

My BS3 is in V.OPT 2

Have you assigned speaker types and roles? (under SOUND SETUP)?

And ‘default video speaker’ (under SOUND ADJUSTMENT)?

J.

Can I plug into any S/PDIF input?
I switched to AV1 (it’s active in my service menu).
In LG, I selected optical and passthrough.
Speaker types and roles are assigned—speakers click when selected.
There’s no ‘default video speaker’ option under Sound Adjustment for me. I’m attaching a screenshot.

I’d like to note that the BS3 is almost always in standby mode (flickering orange), as if it’s not receiving the correct sound.

• This reply was modified 1 day, 8 hours ago by Alexey Malyugin.

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[Tignum]

Hi,

You must use the input that you have assigned the remote control to. I am not sure if the Mk3 has the same menu as the Mk1. Maybe you can get hold of a reference manual?

Below a couple of screenshots of my settings:

I assigned the S/PDIF input to the TV command on the remote:

Then under OPTIONS/SOUND, you can see how I listed my speakers, their roles, and their volume & distance settings, also that I want to use all speakers for video use, and 2 speakers for audio use (SPEAKER 5 / SPEAKER 2)

Are you not using a centre speaker? Could it be to better use another powerlink socket? The first two are dedicated to center and sub:

That is pretty much it I guess!

Hope this helps,

Regards Johan

Location: Netherlands
My B&O Icons:

[Tignum]

When you set the ‘TV SPEAKER LEVEL’, do you hear white noise from the speakers? I ask this as you say that they do click.

In case the BL8000s are the only speakers you have connected, you might want to try to connect them as centre speakers, use CONFIG to tell the BS3 that they are a pair of 8000s.

This is from the manual on the B&O site https://support.bang-olufsen.com/hc/en-us/articles/360041518532-Beosystem-3

J.

• This reply was modified 1 day, 6 hours ago by Tignum.

Location: Netherlands
My B&O Icons:

[Alexey Malyugin]

Tignum wrote:

When you set the ‘TV SPEAKER LEVEL’, do you hear white noise from the speakers? I ask this as you say that they do click.

J.

No, they only click when their roles are selected.

[Alexey Malyugin]

Tignum wrote:

Hi,

You must use the input that you have assigned the remote control to. I am not sure if the Mk3 has the same menu as the Mk1. Maybe you can get hold of a reference manual?

Below a couple of screenshots of my settings:

I assigned the S/PDIF input to the TV command on the remote:

Then under OPTIONS/SOUND, you can see how I listed my speakers, their roles, and their volume & distance settings, also that I want to use all speakers for video use, and 2 speakers for audio use (SPEAKER 5 / SPEAKER 2)

Are you not using a centre speaker? Could it be to better use another powerlink socket? The first two are dedicated to center and sub:

That is pretty much it I guess!
Hope this helps,
Regards Johan

I will attach screenshots, as I think the issue might be with the source. This is because standby lights up orange after 5 seconds.

Attachments:

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[Tignum]

Hi, my BS3 led is orange when in use. Did you try to make the BL8000s centre speakers? Are the speaker levels not set to zero?

Regards, J.

Location: Netherlands
My B&O Icons:

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