Hi, I have a brand new freesat box which is connected between a sky dish and a 2004 crt beko tv via a hdmi to scart converter. The picture is replaced intermittently by a multi coloured screen with the audio still playing. I then press the standby button? (top right) on the remote, then press it again and both picture and sound come back. I checked for a good satellite signal first by connecting the sky box and it was ok. When I did the first time installation the signal strength & quality was good. Any idea what I can do to stop this?