jeana1980,

It sounds like an issue with the HDCP technology inside of the cable/sat box. Often times, when the screen goes out, yet the sound stays on, that indicates that the box thinks it may not be hooked up to a panel. This technology is to eliminate the ability to stream the signal to a computer or non-panel device.

Often times, turning off the cable box and letting the HDCP reconnect automatically will do the trick.

--HDTech