TCL Q7 QLED Google TV game mode, 120 Hz or VRR is not working

The checks in more detail

which on the manual is the HDMI 2.1 port, and use an Ultra High Speed HDMI cable. In the TV's settings, under Settings, Channels and Inputs, External inputs, HDMI, enable the full HDMI mode for that port, often called HDMI 2.1 or Enhanced format. Then set the picture mode to Game, which cuts processing and is needed for VRR to work. On a PlayStation 5 or Xbox Series console, turn on VRR in the console's display settings, and on a PC enable it in the graphics driver.

The Q7 also has a game bar, opened by holding the menu button with three lines on the remote while in game mode, which lets you choose the high frequency mode, such as 144 Hz at 4K, and shows the signal's refresh rate. If the bar reports the input as 60 Hz when you expect 120 Hz, the source is not sending it, so check the console's video modes.

RTINGS' measurements note that the response time is less consistent while VRR is active, so some players prefer VRR off for fast games and a fixed 120 Hz instead; test both. Some games flicker or the picture goes black briefly when VRR toggles, a known side effect with certain consoles, so update the TV and the console. If VRR still will not engage, try another cable and port, reset the picture to defaults, and check the TV's firmware in Settings, System, About. A black screen at 144 Hz means the cable cannot carry it, so lower the mode.