To troubleshoot a Smart TV that is not displaying any sound or picture, there are some steps you should take:

1. Check that the power outlet is working.
2. Check that theTV is plugged in correctly and securely.
3. Check the settings on the TV itself and the connections.
4. If possible, try a different input or connect to a different device.
5. Disconnect the TV from the power source for at least one minute.
6. Check the manufacturer’s website for any software updates.