One of our TVs (quite an old one) has developed a problem where if I am watching satellite TV (the satellite receiver is connected to the TV via a SCART lead), I can hear both the terrestrial channel and the satellite channel. I can get around this by keeping the TV on the video channel and using the AV channel on the video, but I'm curious what's going on. A bad solder joint somewhere at the SCART connector on the TV board, or something more serious?