Troubleshooting a Smart TV that is not responding to the power button:

1. Check to see if the TV is plugged into a power outlet and is switched on.
2. Check the power cable and confirm that it is connected correctly to the back of the TV and the plug.
3. Reset the TV by unplugging the TV from the power outlet and then plug it back after a couple of minutes.
4. Check the remote and see if the power button is working.
5. Check the batteries in the remote.
6. Restart the TV.