problems with pc display , Please help

Hi guys , a few months ago i bought a nvidia 6600GT the card as been flawless. 2 months ago i bought a samsung 27 inch LCD HD tele to mainly play the xbox 360 on. i now use the HD tv as my pc screen but the last few days the tv as been turning off and going into standby mode while playing world of warcraft, the pc is still running when this happens but i have no display on the tv. could this be the tv or the gfx card? before i had the card i used a ATI 9800 pro and had problems with that when i use to boot up pc i had the NO DISPLAY message on screen so i knew that was the card so thats whats making me think this time it may be the screen. what do you suggest or think it may be. also this does not happen while im browsing the net only when i play world of warcraft. many thanks for reading hope some 1 can help .

i would say it was the tv being fussy about the signal its receiving. mine does this too, and it only does it in games, and it does it regardless of what graphics card is feeding it. the problem seems to occur when you finish a level (any game really) and the graphics card flicks the resolution to one that the tv doesnt support, then flicks it back again and the tv doesnt respond, in the end, i had to run it at 1024x768 for it to not do it, but it still looked pretty good :)

Right guys ive come to the conclusion that its the gfx card as ive used an old CRT monitor and its not turning off. ive installed some new drivers for the gfx card and installed the latest version of direct x but yet the problem is still happening. can you recomened trying/doing anything else. many thanks. !!