Follow these steps to troubleshoot a flickering or flashing screen on your Smart TV:

1. Check if the screen display mode is causing the issue, and change the display mode if necessary.
2. Run a Picture Test on the TV to determine if the issue is caused by the TV or a connected device.
3. Adjust the brightness and contrast settings on your Smart TV.
4. Update the firmware on your Smart TV.
5. Unplug the TV and wait 15 minutes before plugging back in.
6. Reset the TV to its factory settings.