LG OLED C1/C2 Soundbar Has No Audio: Fix ARC and eARC Setup

Quick Answer

For an LG C1/C2 soundbar that powers on but produces no sound, connect the TV's HDMI port physically labeled ARC/eARC to the soundbar port labeled HDMI OUT (TV ARC/eARC)—not an ordinary HDMI input. Select HDMI ARC Device as LG Sound Out, enable SIMPLINK (HDMI-CEC), and begin with a known stereo PCM source. Enable eARC only if the soundbar supports it, then introduce Dolby formats and external players one at a time.

This proves basic return audio before codec pass-through or multi-device control complicates the path. If TV speakers are silent too, ARC is not the first fault. If internal webOS apps work but one console does not, investigate that source's output. Do not factory-reset the TV before verifying ports and a two-device baseline.

Symptoms and Their First Branch

The soundbar turns on with the TV but remains silent: control works; audio return may not.

LG shows a muted external-speaker icon: Sound Out or ARC discovery may be wrong.

Internal apps have no sound, but a player connected directly to the bar works: return path is implicated.

Internal apps work, but PS5/Xbox/Apple TV is silent: source format or topology is implicated.

Optical works while HDMI ARC does not: speaker hardware is functional; inspect ARC/CEC.

PCM works but Dolby/DTS is silent: codec support or pass-through is the branch.

Sound returns after toggling inputs or unplugging HDMI: wake/CEC state may be stale.

Video and audio both fail through the soundbar: its HDMI video pass-through or source link also matters.

Record the complete soundbar model, which physical ports are used, C1/C2 firmware, source, app and format shown by the bar. “HDMI connected” is insufficient because many bars separate TV output from source inputs.

Causes Ordered by Setup Probability

Wrong HDMI port or cable direction

On C1/G1 and C2/G2, ARC/eARC is associated with the TV's labeled HDMI 2 port. The soundbar end normally uses HDMI OUT/TV ARC, even though audio returns from TV to bar. Connecting TV HDMI 2 to the bar's HDMI IN may pass a source in another topology but does not establish the expected return channel.

Wrong LG Sound Out

The TV can target its speakers, optical, Bluetooth or HDMI ARC. A bar can power via CEC while LG still sends audio elsewhere. Output selection and volume control are separate evidence.

SIMPLINK/CEC is disabled or conflicted

ARC systems commonly rely on HDMI-CEC system-audio control. LG calls it SIMPLINK. Another streamer or console can issue power/input commands that change the audio destination. CEC does not carry audio, but its state can determine which device receives it.

ARC/eARC capability mismatch

ARC and eARC are related but not identical. A legacy ARC bar should be tested with LG eARC Support off. An eARC bar can use eARC for higher-capacity formats and capability discovery. Turning eARC on cannot upgrade an ARC-only product.

Unsupported audio format

Stereo PCM is the broad baseline. Streaming Atmos commonly uses Dolby Digital Plus; disc Atmos can use Dolby TrueHD. C1/C2 DTS behavior differs from newer LG models. Pass Through cannot make the television or soundbar understand an unsupported codec.

Topology and source configuration

A source connected to the TV depends on TV return audio. A source connected to the soundbar depends on its HDMI input and video pass-through. Console device type, speaker layout and bitstream selection must match the actual wiring.

Step-by-Step Safe Fix

1. Prove the TV has audio

Select TV Speaker and play LG menu sounds or a known internal app. If silent, run LG Sound Self-Diagnosis and test another app/source. A system-wide C1/C2 audio failure is not solved by changing ARC cable.

2. Build a two-device topology

Disconnect every console, streamer and disc player. Connect only TV HDMI 2 ARC/eARC to soundbar HDMI OUT (TV ARC/eARC). Remove optical and Bluetooth so the bar cannot switch automatically. Choose the soundbar's TV/ARC input.

Use one short known-good HDMI cable, seated without adapters. Ultra High Speed certification is useful for broader HDMI 2.1 video use, but an expensive cable does not add ARC/eARC support to hardware.

3. Select Sound Out and SIMPLINK

On installed webOS, select the wired HDMI ARC device under Sound Out. Enable SIMPLINK/HDMI-CEC in external-device settings. C1 uses webOS 6 organization and C2 uses webOS 22; menu wording can move after updates, so follow descriptions rather than copied screenshots.

Confirm the bar wakes and volume commands reach it. Those events prove CEC control, not yet audio decode.

4. Establish ARC with PCM

Disable eARC Support temporarily and choose stereo PCM for a basic ARC test. Play an internal app. If sound appears, ports, control and return audio function. If the bar is ARC-only, this may be the correct baseline. If still silent, reseat the cable with devices powered down, then test another direct cable.

5. Enable eARC only when supported

Read the bar manual/specification. If it explicitly supports eARC, enable LG eARC Support and verify recognition. Test PCM again before Dolby. ARC success plus eARC failure points to eARC interoperability, firmware or cable—not a dead speaker.

6. Add audio formats deliberately

Set Digital Sound Output to Auto or Pass Through based on the documented downstream support. Start with Dolby Digital, then Dolby Digital Plus/Atmos from a confirmed title. Read the soundbar information screen. If PCM works but one codec does not, return to source decoding or a supported alternate track instead of repeatedly power-cycling.

Do not diagnose DTS silence as generic ARC failure on these generations. Use a compatible PCM conversion or direct-to-receiver route where appropriate.

7. Add sources individually

Reconnect one source to the TV. Test its menu and known content, then standby/wake. Configure its HDMI audio device type and format for the actual soundbar/receiver. Add the next source only after the first remains stable. If a newly added box causes output to return to TV Speaker, test only that box's CEC power/audio-control setting.

8. Compare direct-to-soundbar routing

If the bar has HDMI inputs, connect the failing source directly to it. Stable audio there implicates TV pass-through/return or source capability negotiation. Before retaining this topology, verify that the bar passes the required 4K120, VRR, HDR10 and Dolby Vision video. Many older bars cannot pass every gaming feature.

9. Update, then reproduce cleanly

Record firmware for TV, bar and source and install stable public releases. Perform one ordered restart: power down, disconnect extra HDMI devices, start TV and bar, confirm ARC, then add sources. If the fix lasts only until standby, follow the dedicated Atmos/standby or eARC-dropout diagnosis and report the wake sequence.

When Not to Change Formats

If all supported content works and only the front display lacks an Atmos label, verify the bar's app before changing anything. If only one language track is silent, select another known track. If optical works and meets a simple stereo use case, it is a safe fallback, but it removes eARC's higher-format capability and usually changes CEC volume/power behavior.

Do not alter AV Sync to restore missing audio; delay controls continuous sound. Do not enter the service menu, disable OLED protection, run Pixel Cleaning or copy picture settings. None establishes ARC.