any ching uses HTPC with Yamaha 3020 have audio playing problem, when turn off the LCD TV . the main screen (OS window 7 ) switch/ disppear on monitor...thanks for your comment and solution
HTPC with HD6870..hdmi to AMP(video and audio)
Samsang LCD TV
Set PC monitor to Main and LCD to extend display
Play movie - audio and video ok
Play Music : sound ok , Main screen (monitor) only normal when LCD TV on
When LCD TV off, main screen (monitor)disappear or switch to LCDTV