Sky + box turning off my tv?

Hi, my Sky+ box is turning off my tv,(not just the picture). Turn the tv back on with the remote and a minute later off it goes again.It will do this for a few times then settle down for about an hour or more and start again. I have run the tv with dvd player and sky box switched off and it works fine. Anybody had similar probs or know of a solution? thanks

Phil
December 2013