If your LG S90QY Dolby Atmos not working, the problem is usually a settings mismatch, a connection issue, or a source that is not actually sending Atmos.
This guide walks through the most common causes and the fastest fixes so you can restore immersive audio without guesswork.
What Dolby Atmos requires on the LG S90QY
Dolby Atmos is not just a soundbar feature; it depends on the entire playback chain.
The LG S90QY can decode Atmos, but the TV, app, streaming device, game console, or Blu-ray player must also output a compatible signal.
For Atmos to work correctly, you typically need:
- A source that supports Dolby Atmos
- A connection method that can pass the signal, usually HDMI eARC/ARC or direct HDMI to the soundbar
- The correct audio settings on the TV, soundbar, and source device
- Content that is actually encoded in Dolby Atmos
If any one of these parts is wrong, the system may fall back to stereo, Dolby Digital, or PCM instead of Atmos.
Why LG S90QY Dolby Atmos not working is so common
Many users expect the soundbar to automatically switch to Atmos whenever a movie or game starts.
In reality, several devices can strip or downmix the audio before it reaches the soundbar.
That is especially common with built-in TV apps, external streaming boxes, and HDMI port settings that default to standard ARC behavior.
Another frequent issue is confusion between “sound is coming through” and “Atmos is active.” The LG S90QY may still play audio while showing a non-Atmos input format such as PCM or Dolby Audio.
Check the source first
The simplest way to troubleshoot is to verify the content itself.
Not every title labeled “premium” includes Dolby Atmos, and not every platform delivers it on every plan or device.
Confirm the content includes Atmos
Look for the Dolby Atmos badge on the streaming service title page.
On services like Netflix, Disney+, Apple TV+, Prime Video, and Max, Atmos availability can depend on the title, subscription tier, and playback device.
Test with a known Atmos title
Use a reliable reference title known to output Atmos, such as an Atmos-enabled movie on Apple TV+ or Disney+.
If that works, the problem is likely with your previous source rather than the LG S90QY.
Verify the TV audio settings
On LG televisions, incorrect audio output settings are one of the most common reasons LG S90QY Dolby Atmos not working.
The TV must be configured to pass a high-quality bitstream to the soundbar instead of converting the signal first.
Set digital sound output correctly
On many LG TVs, go to the sound settings and make sure the digital audio output is set to Passthrough or Auto, depending on the model.
Avoid settings that force PCM if you want Atmos over HDMI.
Enable eARC when available
If your LG TV and LG S90QY both support eARC, turn it on.
Enhanced Audio Return Channel provides more reliable support for higher-bandwidth audio formats than standard ARC.
- Turn on eARC in the TV sound menu
- Make sure the soundbar is connected to the TV’s HDMI ARC/eARC port
- Use a certified HDMI cable rated for high-speed or ultra-high-speed use
Check internal speaker and external output behavior
Some TVs retain odd audio routing preferences after a software update or power interruption.
If the soundbar is connected correctly but Atmos still fails, switch the TV output temporarily to internal speakers and then back to HDMI ARC/eARC.
Inspect the HDMI connection
Physical connection issues are easy to overlook, especially when basic audio still works.
Atmos is more sensitive than stereo output, so a cable or port problem can prevent the format from passing properly.
Use the correct HDMI port
Connect the LG S90QY to the TV’s HDMI port labeled ARC or eARC.
If the soundbar is connected to a regular HDMI input instead of the return-channel port, Atmos from TV apps usually will not work as expected.
Swap the HDMI cable
A worn or low-quality HDMI cable can cause intermittent audio negotiation failures.
Replace the cable with a known-good certified HDMI cable and test again.
Try a direct source connection
If you use an external device like an Apple TV 4K, Roku Ultra, PlayStation 5, Xbox Series X, or Blu-ray player, test connecting it directly to the soundbar or to the TV through the recommended path for your setup.
Some devices work better when connected one way versus another, depending on the TV’s HDMI passthrough support.
Check the soundbar audio mode
The LG S90QY includes audio modes and processing options that can affect how surround formats are displayed.
If the soundbar is in a mode that forces upmixing or a simplified output path, Atmos may not be indicated properly.
- Set the sound mode to a standard or movie-oriented mode for testing
- Disable features that alter the input signal during troubleshooting
- Confirm that the soundbar display or app indicates the incoming format
Use the LG Sound Bar app, if available for your region and model, to review status and settings.
The app can help confirm whether the soundbar is receiving an Atmos-capable signal.
Streaming apps can block Atmos unexpectedly
Built-in smart TV apps are convenient, but they are also a common source of compatibility issues.
A title may support Atmos in the app on one device but not on another, even if the content is identical.
Update the streaming app
Outdated app versions can break audio handshakes or remove Atmos support temporarily.
Update the app, sign out and sign back in, and test again.
Check subscription and device limits
Some platforms require a higher-tier subscription for Atmos playback.
Others only send Atmos through specific devices or formats, such as certain smart TV models, streaming sticks, or set-top boxes.
Restart the app and the TV
Close the app completely, power off the TV, unplug it for a minute if needed, and restart the soundbar.
This clears temporary handshake errors between the app, TV, and HDMI audio path.
Update firmware on both devices
Firmware bugs can affect HDMI-CEC, eARC negotiation, and Dolby decoding.
If your LG S90QY Dolby Atmos not working after a recent change, check for updates on both the TV and soundbar.
- Update the LG S90QY firmware through the LG Sound Bar app or USB method if needed
- Update your LG TV system software
- Power cycle both devices after the update
After updating, recheck the sound output settings because software updates sometimes reset audio preferences.
Test with different sources to isolate the problem
When troubleshooting Atmos, source comparison is one of the fastest ways to find the failure point.
Try at least three scenarios: a built-in TV app, an external streaming device, and a physical disc player or game console.
- If Atmos works on one source but not another, the issue is source-specific
- If Atmos fails everywhere, the issue is likely settings, cabling, or firmware
- If only TV apps fail, focus on eARC and TV audio output settings
This method helps you avoid changing too many variables at once.
Reset audio and HDMI handshakes
HDMI-CEC and eARC can occasionally get stuck after a power outage, firmware update, or device swap.
A full handshake reset often restores Atmos support.
Power cycle in the right order
- Turn off the TV, soundbar, and source device
- Unplug all devices from power for 60 seconds
- Reconnect the HDMI cable securely
- Power on the TV first, then the soundbar, then the source device
If the issue persists, disable HDMI-CEC briefly, then turn it back on.
This can force the devices to renegotiate control and audio routing.
When the problem is not actually Atmos
Sometimes users assume Atmos is broken when the source is outputting multichannel PCM or standard Dolby audio by design.
That does not always mean a fault exists.
Gaming consoles, for example, may use different audio modes depending on the title and system settings.
Also, some TVs and soundbars do not always display “Atmos” in a way that is obvious.
The absence of a label on one screen does not always mean the format is missing, so confirm with a known test title and the soundbar status display.
Quick checklist for LG S90QY Dolby Atmos not working
- Confirm the content actually includes Dolby Atmos
- Use the TV’s HDMI ARC/eARC port
- Set TV digital audio output to Passthrough or Auto
- Enable eARC on the TV and soundbar if supported
- Replace or test the HDMI cable
- Update TV, soundbar, and app firmware
- Restart all devices and recheck the handshake
- Test a different Atmos title and a different source device
By following these checks in order, you can usually identify why Atmos is missing on the LG S90QY and restore the correct surround format without changing your whole setup.