Is ordinary coaxial cable suitable for a flat

Coaxial cable does not carry video signals but rather rf-signals
To use coax you will have to tune like you are searching for a signal from your aerial..
If you prefer to use video then you will have to use a video cable either rca or hdmi. you can then choose video or hdmi from the remote

Len

Is your TV aerial plugged in. Do you know if it works. Are you tuning the digital stations (you should be. There are no analogue transmissions any longer)

what is the impedance of the cable used from tv to aerial coaxial socket at wall. you may need a Aerial type coaxial cable at 75 ohms you may have used a video cable which looks exactly the same but is different electrically due to impedance differences.

if you hooked up the coaxial in the RF tuner then you can not get signal, the cause will be the tuner has problem.

You have selected an input on the display that is not getting any signal that the display can recognize. Press the source button either on the set or on the remote until you get a signal.

In this case, your VCR becomes the cable channels tuning device for your TV, the better connection should be from your cable box output to your antenna/cable TV input with the coaxial cable, surely, your TV has a better cable tuner than your VCR, to connect the VCR to TV you can use its AV outputs to an available AV inputs of your TV, you can get a better sound and picture in this way.

Problem is with your ISP/Cable Company accepting the installation as one with HD clients, which while
not necessarily costing you more, must be specified to the cable box by your installer.

Make the call.

Your display box continues to pop up because of the way your optimum box is connected to the back of your television. If you are connected with a coaxial cable from the box to the back of the tv, you will get that display box. The reason you are getting it because of the weak signal coming from your coaxial cable(which is the worst cable to use when connecting ANYTHING to ANY tv, especially a lcd tv). That cable is sending a fluctuating signal and your television is adjusting to that(hence the reason the display box comes up). Use composite cables(typical red, white, and yellow cables) to connect your box to your television and I guarantee your problem will be solved. Make sure you unplug that coaxial connection from your box to the television.

You may need an extra HD tuner for your TV. The only problem that you may have would be the original signal running through the coaxial cable. If it's just regular TV stations, the tuner should fix the problem.