The Digital TV Hub(CM-7002) has two HDMI ports on the back of the unit. "HDMI IN" “From Streaming Device”. and "HDMI OUT" "Ton Streaming Device".
If you are seeing a black screen it is possible that you connected the HDMI cable from the CM-7002 to the wrong HDMI input on your TV.
It is possible that you have connected the HDMI cable to the wrong HDMI port on the CM-7002.
Make certain that the Antenna cable actually has Antenna Signals or Un-encrypted Cable TV signals on it.
Please see the image below from the User Guide to help see which ports are used for each device.
If after you have verified that the HDMI cable is connected properly and you are still seeing a black screen or no signal, please verify that the Digital TV Hub(CM-7002) is connected to power. If you do not see 4 dashed lines or the clock displayed on the front of the unit, then the device is not receiving power. Be sure that the outlet you are using is a functioning outlet. Also, be sure that you have the power supply connected in the back of the Digital TV Hub(CM-7002).
If you have verified that all is connected properly, please contact our Channel Master support team to further troubleshoot the problem.