Why an LG Soundbar Gets Stuck on Optical
If your LG soundbar is stuck on optical, the problem is usually not the soundbar itself but the way it is receiving or detecting audio from the TV.
The issue often comes from input selection, a damaged optical cable, a TV audio setting, or HDMI-ARC conflicts that keep the soundbar from switching correctly.
LG soundbars support several connection types, including optical digital audio, HDMI ARC, Bluetooth, and on some models Wi-Fi and AI Sound Pro features.
When one of these paths is misconfigured, the soundbar may keep defaulting to optical even when you want HDMI ARC, Bluetooth, or another source.
What “Stuck on Optical” Usually Means
On most LG soundbars, “optical” refers to the TOSLINK optical input used for digital audio from a television, streaming device, or console.
If the display always shows OPT or Optical, the unit is likely locked onto that input because it is actively detecting a signal or because another source cannot take priority.
- The soundbar stays on optical after switching inputs
- TV audio plays only through optical, not HDMI ARC
- The soundbar ignores remote input changes
- Bluetooth or USB will not become the active source
This behavior can happen on models such as the LG S-series, SN-series, and older SK and SL soundbars, especially when the TV and soundbar are both trying to control audio routing through CEC or ARC features.
Check the Physical Connections First
Start with the simplest cause: the cable path.
Optical audio is sensitive to connection quality, and even a slightly loose connector can keep the soundbar in optical mode.
Inspect the optical cable
- Make sure the cable is fully seated in both the TV and soundbar ports
- Check for bent ends, cracks, or heavy kinks
- Confirm the red light is visible at the cable tip when disconnected from one end
- Replace the cable if the ends feel loose or the plastic latch is damaged
Remove extra audio connections
If both optical and HDMI ARC are connected at the same time, the soundbar may keep prioritizing optical audio.
Disconnect unused cables, then power-cycle the TV and soundbar so they renegotiate the active audio path.
Verify the Correct TV Audio Output Settings
Many cases of an LG soundbar stuck on optical start in the TV menu.
If the TV is still set to optical output, the soundbar may keep receiving that signal even after you try to switch inputs.
Common TV settings to review
- Sound Out: Set to HDMI ARC or eARC if you want to use the HDMI port
- Digital Sound Output: Try PCM, Auto, or Pass Through depending on your devices
- SIMPLINK on LG TVs: Enable if using HDMI ARC
- External Speaker: Make sure the TV is not forcing a different audio device
On LG televisions, HDMI ARC typically requires SIMPLINK to be enabled.
Without it, the TV may default back to optical or internal speakers even when the soundbar is connected by HDMI.
How to Switch the LG Soundbar Away from Optical
Use the soundbar remote or the top-panel controls to move to the desired source, then confirm the TV is outputting audio correctly.
If the model supports it, input changes should cycle through Optical, HDMI ARC, Bluetooth, and other sources.
- Turn off the TV and soundbar
- Disconnect power from both for 60 seconds
- Disconnect the optical cable temporarily
- Reconnect only the source you want to use
- Power on the TV first, then the soundbar
- Select the correct input manually
This reset often clears a stuck input state, especially after a firmware update, power outage, or HDMI handoff failure.
HDMI ARC and eARC Problems That Mimic Optical Lock
Sometimes the soundbar is not truly stuck on optical; instead, HDMI ARC is failing and the system falls back to optical as the active route.
ARC issues are common because they depend on both audio signaling and device communication over HDMI-CEC.
What to check on HDMI ARC
- Use the TV’s HDMI port labeled ARC or eARC
- Use a high-speed HDMI cable in good condition
- Enable CEC features such as SIMPLINK on LG TVs
- Turn on ARC or eARC in the TV audio menu if available
- Power-cycle both devices after making changes
If the soundbar works over optical but not HDMI ARC, the issue may be the TV port, the cable, or a CEC conflict with another connected device such as a gaming console or streaming box.
Firmware and Software Issues
LG soundbars and LG TVs can develop source-detection glitches after firmware changes.
A software mismatch may cause the soundbar to hold onto optical input or fail to recognize an alternate source.
- Check for the latest LG soundbar firmware in the LG ThinQ app or support site
- Update the TV firmware through the TV settings menu
- Restart both devices after updating
- If the issue began after an update, perform a full power reset
Some models also benefit from a factory reset after firmware updates, especially if the audio source was changed multiple times during setup.
Use the Soundbar Reset if Nothing Else Works
If basic troubleshooting fails, a factory reset can clear retained settings that keep the device locked to optical.
This is useful when the soundbar behaves normally except for input selection.
Before resetting, note the following
- Wi-Fi and Bluetooth pairings may be erased
- Custom EQ and sound modes may return to default
- Paired subwoofers or rear speakers may need to reconnect
After the reset, reconnect the soundbar as if it were new.
Then test only one audio path at a time so you can tell whether optical, HDMI ARC, or Bluetooth is functioning correctly.
When the Optical Port Itself Is the Problem
If the soundbar only receives sound through optical and refuses every other input, the optical port, internal selector, or main board may be defective.
Signs of a hardware issue include intermittent audio, no response to source changes, or an optical indicator that never clears even after a reset.
In that case, test the soundbar with a different TV or optical source.
If the behavior is identical across devices, contact LG support or a qualified repair center.
For units under warranty, document the troubleshooting steps and keep serial numbers, purchase details, and photos of the connections ready.
Best Practices to Prevent the Problem
Once the soundbar is working normally, a few setup habits can reduce the chance of it getting stuck on optical again.
- Use one primary audio path instead of multiple competing connections
- Keep HDMI ARC settings consistent on both TV and soundbar
- Avoid unplugging cables while devices are powered on
- Update firmware periodically for both the TV and soundbar
- Use quality HDMI and optical cables with secure ends
For LG home theater setups, stable input behavior depends on clean cabling, matching audio settings, and a clear signal chain from the TV to the soundbar.
If you are switching between devices often, take a moment to confirm the TV output mode before assuming the soundbar is faulty.
Quick Troubleshooting Checklist
- Confirm the optical cable is secure and undamaged
- Remove extra audio cables and test one connection at a time
- Set the TV sound output to the correct device
- Enable SIMPLINK or CEC for HDMI ARC
- Power-cycle the TV and soundbar
- Update firmware on both devices
- Factory reset the soundbar if needed
- Test for possible hardware failure if the issue remains