A:Answer Does the cable box have an HDMI output? If it is connected with composite or component video outputs, these cannot display through HDMI; you would need to run a cable from Monitor Out to the composite input on the TV. If the cable box does have HDMI and it is connected to HDMI 2 for instance, ensure that the TV is connected to the HDMI output on the receiver, and that the receiver has HDMI 2 selected.