Here are some steps you can try to resolve the issue:
- Make sure that your Onn 4k streaming box is properly connected to your TV and that both devices are turned on.
- Check that the HDMI cable is securely plugged into both the Onn 4k streaming box and your TV.
- Try changing the HDMI input on your TV to ensure that you have selected the correct input for the Onn 4k streaming box.