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 5 hours, 5 minutes 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:

You must be logged in to view attached files.

[Author]

Posts