Presumably the resolution of the EM7680 is currently too high than the receiver can handle.
- connect the EM7680 directly to the TV and lower the resolution of the media player.
- navigate in the main menu to the cogwheel and then to "System".
- behind "Display" the resolution can be reduced.
Now reconnect the EM7680 to the amplifier (receiver).
For a good test, also use the original HDMI cable of the EM7680.