Follow these steps to connect your Smart TV to a DVR or cable box:

1. Connect an HDMI cable from the video source, such as a DVR or cable box, to the HDMI port on your Smart TV.
2. On the video source, press the Output or Play button to show your display.
3. Open the settings menu on your Smart TV, which is usually represented by a gear icon.
4. Select the correct video input option from the list of source options on your Smart TV.
5. Press the Guide button on the video source remote to begin viewing programming.