Screen saver

Sorry if this has been covered before but I can’t find anything on it.

If I’m streaming music from my computer to the WD Live which is connected to the plasma witha HDMI cable, how can I get the screen saver to operate? It should come on after 5 mins but doesn’t. I don’t waqnt the plasma screen to burn in if I’m playing a lot of music.

*bump*

anybody ?