Try rebooting your box if it is a V6 there is a switch right rear put that off unplug leave for a couple of minutes then switch it back on if that does not fix it you will need to call them to log a complaint also ensure that all cables are pushed in securely
Thank you for the reply.. Yes, went into settings and altered a few things( maybe the audio/pcm).. Switched off the box and rebooted.. We have sound on all channels and this also cured a minor sound issue we had where you had to keep turning up the volume to high for some of the channels.. Cheers for the advice..