how can I stop my screen breaking up into pixels and skipping?

when i am watching tv through sky, occasionally my screen breaks up into pixels and jumps sound and vision. How can i stop this?
carol wilson, June 2004


done
One simple cause of this can be that your Set-Top-Box is getting too warm. My Grundig Sky Box would do this if I didn't let it breathe. Make sure the air can get to it. If nessesary, take it out of a TV cabinet.

Ian Kelp, June 2004