I have a commitment for the next couple of hours or so then will tackle it starting with the connectors. Thank you.
Have connected everything by the book, aerial, HDMI, ethernet, power, turned on the remote and box has green light, turned on TV with its remote and screen shows No Signal. So will now turn off and disconnect again.
So you've connected the aerial feed to the input socket on the Pro Box and connected the output socket on the Pro Box to the TV's aerial input. And the HDMI socket on the Pro Box to one of the HDMI sockets on the TV.
Are you getting "no signal" when the TV is switched on and the Pro Box is not and you are expecting to watch programmes just on the TV
OR
The Pro Box is on and the TV has been switched to the HDMI input from the Pro Box?
Which one?
The box is switched on, the TV is switched on, the HDMI cable is connected from the box to the TV port. It says No Signal, there are no on screen instructions.
Have you set the tv to the correct HDMI "channel"?
From your newest description of your setup and what you have tried it appears that it is waiting for instructions from you.
Use the TV remote to tell it which HDMI port the Cello should be looking for a signal from.
Looking at a picture which claims to be for an original Cello TC3220F remote this will be via a button marked "Source" which is located in the centre of the remote immediately above the row of coloured buttons.