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If your KEF system is connected to a TV but silent, select TV mode, use the television’s ARC/eARC HDMI socket, enable HDMI-CEC, and set HDMI audio output to PCM. Then reseat or replace the cable, power-cycle the TV, and use optical PCM as a fallback if HDMI remains silent.
Start with the settings most likely to restore sound
A silent KEF TV setup is usually a source-selection, HDMI handshake, audio-format, or cable problem. Work through the checks in this order so you change one variable at a time:
- Switch the KEF device to TV mode and confirm that the TV icon or TV-mode indicator is showing.
- Confirm the television cable is plugged into the TV’s socket marked ARC or eARC, not an ordinary HDMI input.
- Turn on HDMI-CEC in the television’s settings. Samsung calls this feature Anynet+; LG calls it Simplink.
- Set the television’s HDMI audio output to PCM. If the television is set to Dolby Digital or another bitstream mode, PCM is the recommended troubleshooting setting.
- Check the audio format selected inside the streaming app. Netflix and Disney+ are specifically identified in KEF’s LSX II LT support guidance.
- For eARC, use a high-speed HDMI cable with Ethernet. Reseat both ends; replace the cable if the indicators still show that the connection is missing.
- Unplug the television for about 10–15 seconds, reconnect it, and test again.
Keep the KEF system powered on, unmuted, and at an audible volume while testing. These checks apply to KEF TV-audio systems covered by the cited support instructions; indicator colors and names can differ by model.
Confirm that the KEF system is listening to the TV
Select TV mode
Use the KEF remote, control, or the available source selector to choose TV. The TV icon or TV-mode indicator should appear. A system left on another input can be fully powered and apparently connected while producing no sound from the television.
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Check power, mute, and volume before changing cables
Make sure the KEF unit is on, mute is disabled, and the volume is high enough to hear. KEF’s troubleshooting notes call out muted mode because the indicator may blink even when the HDMI connection itself is fine. If the system responds to volume commands but remains silent, continue to the HDMI checks rather than assuming the speakers have failed.
Use the television’s ARC or eARC port and complete the CEC handshake
Plug into the labeled port
Audio return works only through the television’s HDMI socket labeled ARC or eARC. Move the cable to that socket if it is in a regular HDMI input. On the KEF side, connect the cable to the HDMI port intended for TV return audio.
Interpret the TV indicator
A blinking TV or light-blue indicator means the TV/HDMI connection has not been found. A pulsing TV or light-blue indicator means HDMI-CEC is present, but ARC audio has not been established. That distinction matters: a pulsing light points toward television audio-return settings, while a blinking light points first toward the port, cable, or physical connection.
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Open the television’s connected-device or HDMI settings and enable HDMI-CEC. The name varies by manufacturer. On Samsung televisions, look for Anynet+; on LG televisions, look for Simplink. After enabling it, switch the TV and KEF system off and on, then reselect TV mode.
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CEC is the control and discovery part of the handshake. A television can detect an HDMI device yet still fail to send ARC audio if CEC is disabled or if the ARC negotiation did not complete.
Set HDMI audio output to PCM
Change the TV’s digital audio format
In the television’s sound or digital-audio-output menu, choose PCM for HDMI audio. KEF’s official troubleshooting wording is: “Make sure the audio output of HDMI is set to PCM (this is often set to Dolby Digital by default).” The setting may be called Digital Audio Output, HDMI Audio Format, or a similar label depending on the TV.
PCM is the safest diagnostic format for this failure because it removes a Dolby Digital or other bitstream compatibility variable. Do not switch back to Dolby Digital until PCM playback is working and you have a reason to test another format.
Check the streaming app’s own audio choice
A TV-wide PCM setting does not always override an audio track selected inside an app. Open the playback audio and subtitle menu in the affected service and choose a PCM-compatible or stereo track when available. KEF’s LSX II LT FAQ specifically names Netflix and Disney+ as apps whose audio format should be checked when HDMI functions work but sound is absent.
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Use the result to isolate the fault
- If PCM restores sound from every TV source, the previous format was the trigger.
- If the TV menu produces sound but one streaming app remains silent, investigate that app’s selected track or restart the app.
- If no source produces sound and the indicator still pulses, return to CEC, the ARC/eARC port, and the cable.
Check the eARC cable and both physical connections
Use the specified cable type
For HDMI eARC, KEF specifies a high-speed HDMI cable with Ethernet. Lower-quality or damaged cables may fail to establish the connection even when the plugs appear fully inserted. If your existing cable is suspect, look for a high-speed HDMI cable with Ethernet that is described as eARC/ARC compatible; replacement is a troubleshooting step, not a guaranteed repair.
Reseat, then replace
- Turn off the television and KEF system.
- Remove the HDMI cable from both devices.
- Inspect the plugs for damage and reconnect them firmly to the TV’s ARC/eARC socket and the KEF TV-return socket.
- Power the devices on and wait for the indicator to settle.
- If the TV indicator still blinks, test with another known-good high-speed HDMI cable with Ethernet.
A cable swap is especially important when the indicator says the connection is not found, when the setup worked previously and stopped after moving equipment, or when a long or visibly worn cable is being used.
Power-cycle the TV and retry the handshake
Standby is not always enough to clear a failed ARC/eARC negotiation. KEF’s LSX II LT instructions recommend unplugging the television for approximately 10–15 seconds, then reconnecting it and trying again. Use this sequence:
- Mute or pause the TV, then switch off the KEF system and television.
- Unplug the television from mains power for about 10–15 seconds.
- Reconnect the TV and allow it to finish starting.
- Turn on the KEF system, select TV mode, and check the indicator.
- Play a built-in TV source before testing a streaming app.
This restart gives the TV and KEF device a fresh opportunity to discover each other through HDMI-CEC and establish ARC audio.
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Use optical PCM when HDMI remains silent
If the HDMI path still produces no sound after the port, CEC, PCM, and cable checks, use the television’s optical output as a fallback if both devices provide it. Set the television’s digital audio output to PCM, connect the optical cable, select the KEF optical source, and test a built-in TV channel or app.
Optical bypasses the HDMI ARC/eARC handshake, so it is useful for separating a TV-return problem from a broader KEF audio problem. If optical PCM works, the speakers and basic TV audio path are functioning; the remaining issue is concentrated in HDMI port selection, CEC negotiation, cable capability, or HDMI audio-format handling.
Read the indicator before choosing the next fix
| Indicator behavior | What KEF’s guidance indicates | Next action |
|---|---|---|
| TV or light-blue indicator blinking | TV/HDMI connection not found | Verify the ARC/eARC port, reseat both plugs, and replace the cable with a high-speed HDMI cable with Ethernet. |
| TV or light-blue indicator pulsing | CEC is present, but ARC audio is not established | Enable HDMI-CEC, confirm PCM output, and power-cycle the TV. |
| Light-blue and purple indicators blinking on LSX II LT | The device detects a non-PCM signal | Change the TV and affected app audio output to PCM. |
| Muted-mode blinking indicators | The system may be muted | Cancel mute and raise the volume before replacing hardware. |
The LSX II LT indicator descriptions are model-specific. If your KEF product uses different colors, use the same logic—first identify whether it reports no HDMI connection, an incomplete ARC negotiation, a non-PCM signal, or mute.
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Test a built-in TV source
Start with a television channel, internal menu sound, or another source that does not depend on an external HDMI device. If that source works, the KEF connection is probably established and the problem is limited to the external device or app.
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Check app audio independently
For a silent Netflix or Disney+ title, open the title’s audio selector and choose a different available track, then stop and restart playback. Confirm that the TV’s HDMI output remains PCM. If other apps and TV menus play correctly, avoid changing the cable repeatedly; focus on the app’s selected audio track and restart the app or television.
Separate an external HDMI device from the TV return
Disconnect additional HDMI devices temporarily and test the TV by itself. A receiver, game console, or set-top box can alter the television’s output format or CEC behavior. Reconnect devices one at a time after TV audio works, checking whether a particular device causes the silence to return.
Report a persistent failure to KEF with useful diagnostics
If the sequence above does not restore sound, submit a report through KEF Connect App Settings > Support. Include details that let support reproduce the HDMI state:
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- Whether the cable is connected to ARC or eARC and the cable type.
- The input or app being tested.
- Whether the indicator blinks, pulses, shows the LSX II LT light-blue/purple pattern, or indicates mute.
- Whether HDMI-CEC was enabled and whether the TV labels it Anynet+ or Simplink.
- Whether changing HDMI and app output to PCM changed the result.
- Whether a 10–15-second TV power cycle or optical PCM connection restored sound.
These observations distinguish a missing physical connection from a CEC/ARC negotiation failure and from a non-PCM signal, giving support a precise starting point instead of a generic “no sound” description.
Quick Recap
A compact setup checklist
- KEF source: TV mode selected.
- TV socket: labeled ARC or eARC.
- Control link: HDMI-CEC enabled; Samsung Anynet+ or LG Simplink.
- Audio format: PCM on the TV and in the affected streaming app.
- eARC cable: high-speed HDMI with Ethernet, firmly seated.
- Recovery: TV unplugged for about 10–15 seconds, then restarted.
- Fallback: optical output set to PCM if HDMI remains silent.
- Escalation: KEF Connect App Settings > Support with model, input, indicator, cable, and PCM results.
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