This exact same thing happened to my laptop about two months ago. The display was still there (as tested with a flashlight) but no backlighting at all. I would assume the technology is exactly the same between your LCD TV and a laptop LCD monitor. If that's the case, there's a part called an LCD inverter that may have just died. That's what the PC repair ticket indicated on my laptop, anyway.
In my case, the LCD would start working again after a couple of hours. But then it would wink out again as the LCD got hot.
I suspect you'll need to call for a warranty repair.
The spec'd backlight life for that particular LCD is 60,000 hours. I would guess your backlight has failed and will need to be replaced. It fits the symptoms.
I do believe your right, thanks Doc.
Yeah Mark when I did that little test it was like I'll be darn.
