There could be a number of reasons why this is happening.
- You are trying to play Blu-Ray 3D content (see this KB article here)
- Your HDMI cable is bad ( test with other devices )
- Your HDMI adapter is bad ( test with other devices )
- You are playing content that can't scale down to 720P
- You are playing content from a phone/device that is not compatible ( See compatibility list )
- Your phone/media device does not support video out
- Try another HDMI cable
- Make sure your device is compatible
- Try other media devices
- Turn off the Avegant video headset and unplug the HDMI cable. Check your HDMI source to make sure it’s output is set to 720p. Most HDMI devices should automatically sense that the device is 720p and set itself accordingly, but in case it does not, you may want to check the display settings or turn the device off and then on again.