If the TCL QM8 shows a picture but no sound, check that the volume and mute are off and that the TV's speakers are the chosen output. In the sound settings pick between TV speakers, an HDMI eARC/ARC soundbar, Bluetooth and optical, and make sure only one is active. A soundbar on the eARC port needs CEC on and the right input; a Bluetooth headset left connected takes the sound away from the speakers. Set the digital audio format to PCM for a test, since a format the soundbar cannot decode is silent. Restart the TV by unplugging it for a minute, and install updates. If sound is also missing on the built-in apps and the TV test, the speaker hardware needs TCL.
Differential
Likely causes of “TCL TV line has picture but no sound”, and how to tell them apart
- 1
Muted or low volume
What separates it No sound at any level
How to confirm Unmute and raise the volume
- 2
The wrong output
What separates it Sound goes to a Bluetooth device or soundbar
How to confirm Choose the TV speakers or the correct output
- 3
An HDMI or format issue
What separates it Silence on one input only
How to confirm Set PCM and test another cable
- 4
A software glitch
What separates it Sound lost after an update
How to confirm Restart and update
- 5
A hardware fault
What separates it No sound in any app or input
How to confirm Contact TCL
Before you touch a setting
Record this first — changing settings destroys the evidence
- The audio output chosen
- The input and device
- Whether apps and inputs are both silent
Try in this order
0 of 6 completedCheck volume and mute
ReversibleUse the remote.
Check the output
ReversibleOpen sound settings and choose the TV speakers.
Disconnect Bluetooth
ReversibleTurn off connected headsets.
Set PCM
ReversibleChange the digital audio format to PCM.
Restart and update
ReversibleUnplug for a minute and install updates.
Test with a built-in app
ReversiblePlay a built-in app or a streaming app to see whether the sound is missing on every source or only one.
Model-specific
What is true of this model and not of its siblings
- Speakers
- One review describes an Onkyo 2.1.2 speaker system with Dolby Atmos support.
- Outputs
- The QM8 can send sound to its speakers, an eARC soundbar, Bluetooth or optical, depending on settings.
- Other models this page answers
- These steps also fit models QM7, Q6, R655, S555, S455.
Stop boundary
When this stops being a self-service repair
- !If every source is silent with TV speakers selected, contact TCL
Evidence ledger
Sources behind this answer
Input, cable and reset steps.
ARC setup.
CEC control.
Soundbar HDMI issues.
The company and its products.
Exact questions
Common questions
Why is there no sound on one HDMI input?+
The source's audio format may not be supported. Set the source to PCM or stereo.
Why is the QM8 silent after I used a headset?+
The headset may still be connected. Turn off Bluetooth or disconnect it.
Does the QM8 have built-in speakers?+
Yes, an Onkyo 2.1.2 system according to one review, with Dolby Atmos.
How do I test the speakers?+
Play a built-in app or a test tone with the TV speakers selected.
What if only streaming apps are silent?+
Update the app and check its audio settings.
How do I reset the TCL QM8's sound settings?+
Open the sound settings and choose the reset or default option, then check the output again. If it still fails, a power cycle by unplugging the TV for a minute clears many glitches.
Why does sound cut out when I use eARC?+
The soundbar and TV renegotiate the link, which can cause a pause. Use a certified HDMI cable, turn CEC on and update both devices.
Is the sound delayed behind the picture on the QM8?+
A soundbar or Bluetooth headset adds delay. Look for an audio sync or delay setting in the sound menu and adjust it.
Can optical audio be used if HDMI fails?+
Yes. Use the digital optical output if your model has one, with the soundbar set to optical input.
How loud should the QM8's built-in speakers be?+
They are meant for everyday viewing; for a cinema-style sound use a soundbar on the eARC port.