I would like to pretend I'm really smart and knew what I was doing, but my only experience is in buying electronic parts for a relay/switch contractor. But after looking this up on the internet, a lot of people were fixing the lcd tv power problem by simply replacing the capacitors on the power board. A lot. And after looking at the board, it was really a pretty ordinary looking circuit board. And I'm thinking, lcd tv or not, a circuit board is a crcuit board.
Fortunately for me, Sarasota has a real electronics store and we took the board there and right off the bat, he told us that the electolytic capacitors were leaking - a common problem with lcd's tvs he said caused by the cheap capacitors. So there was hope! We replaced the parts and ta da! Still didn't work.
Back to Sarasota Electronics. Larry would test the parts we brought in, go to one of his little drawers and give us correct and better parts. He was very gracious and didn't laugh at us for being umm, not the swiftest repair people he's ever seen.
With his help, we replaced all the electrolytics, and a resistor, and a zener and then and then OMG! It worked.
I wanted to respond as this is forum for people to help others and I found that listening to suppliers and others will make you smarter.
As so many have this problem and parts identifing problems, I want to offer Sarasota Electronics as a source for genuine help with your specific problems.
I wish you all success with your projects and I know the pride that comes from fixing stuff!
Heidi