On the TCL QM8 (2024), variable refresh rate and low-latency game mode depend on three links agreeing: the console or PC, the HDMI cable and the right HDMI input. Use one of the two inputs that support HDMI 2.1 (one review lists inputs 1 and 2) with an Ultra High Speed cable, then turn on the console's VRR and 120 Hz output. On the TV, set the input's picture mode to Game so that Auto Low Latency Mode can switch it, and look for the game bar overlay that shows the refresh rate. If the picture blinks or the sound drops, try a different cable, a lower resolution for a test and the other HDMI 2.1 input. Update the TV software, since TCL has released fixes for VRR behavior.
Differential
Likely causes of “TCL TV line game mode, 120 Hz or VRR is not working”, and how to tell them apart
- 1
The wrong HDMI input
What separates it VRR or 120 Hz is not offered
How to confirm Move the console to an HDMI 2.1 input
- 2
A cable that cannot carry the signal
What separates it Sparkles, black flashes or no 4K 120
How to confirm Use a certified Ultra High Speed HDMI cable
- 3
Game mode off
What separates it Input lag or no VRR indicator
How to confirm Select Game mode or let Auto Low Latency Mode switch it
- 4
The console's settings
What separates it The console reports no VRR
How to confirm Turn on VRR and 120 Hz in the console's video settings
- 5
Old TV software
What separates it Flicker with VRR after an update
How to confirm Install the latest TV software
Before you touch a setting
Record this first — changing settings destroys the evidence
- Which HDMI input and cable are used
- The console's video output settings
- The TV's software version
Try in this order
0 of 6 completedUse an HDMI 2.1 input
ReversibleConnect to input 1 or 2, or the input TCL marks for gaming.
Use a certified cable
ReversibleFit an Ultra High Speed HDMI cable.
Turn on VRR on the console
ReversibleEnable VRR and 120 Hz in its video settings.
Set the TV to Game mode
ReversibleChoose Game mode on that input and check the game bar.
Update the TV
ReversibleInstall the latest software.
Test a lower resolution
ReversibleIf the picture flickers, try 4K 60 Hz to find whether the cable is limiting it.
Model-specific
What is true of this model and not of its siblings
- HDMI layout
- One 2024 review lists HDMI 1 and 2 as HDMI 2.1 and HDMI 3 and 4 as HDMI 2.0, with eARC on a specific port; check the labels.
- Refresh rate
- The QM8's panel is a 120 Hz panel with support for higher rates in gaming modes, per its specifications.
- Other models this page answers
- These steps also fit models Q6, R655, R646, S555, S455.
Stop boundary
When this stops being a self-service repair
- !If VRR flickers on both HDMI 2.1 inputs with a certified cable, contact TCL
Evidence ledger
Sources behind this answer
Google TV settings.
Picture settings.
Google TV tips.
Input, cable and reset steps.
The company and its products.
Exact questions
Common questions
Does the TCL QM8 support 4K at 120 Hz?+
Yes, on its HDMI 2.1 inputs, and it supports VRR for compatible consoles and PCs.
Why does my QM8 flicker with VRR on?+
A cable or an input limit is the usual cause, and sometimes VRR with certain games. Test another cable and update the TV.
What is Auto Low Latency Mode?+
It lets a console switch the TV to Game mode automatically to cut input lag.
Do I need to turn off motion smoothing for gaming?+
Yes. Game mode disables most processing to reduce lag.
Which console settings matter?+
Turn on VRR and the 120 Hz output in the console's display settings.