I have a DCX3200m cable box and I am only getting the volume on my tv. I have tried numerous combinations and cant get a picture. At times the message "This channel is not available pops up" I am on the lower channels so this shouldn't be so. It is hooked up in combination with a Harmon Kardon receiver. The channel number also doesn't show up on my cable box, only the time. I have a few questions. first should the tv be set on cable or tv I have tried both. What setting should the receiver be on for the tv. Is it possible for the tv channels to get out of sync with the cable box?