1. Press the 'Settings' button on the remote control to enter the 'Settings' menu and select the 'Display' option.

2. After entering, you will see two adjustment options: Backlight and Brightness.

3. To adjust the TV's own brightness, increase the Backlight value. If this option cannot be adjusted, check whether Dynamic Eco is turned off.

4. To adjust the brightness of the video input from an external device, increase the Brightness value.