Half a year old means it's still inside the 1 year warranty. So call it in and ask the tech that visits you for a free repair how often he sees this.
I have a Samsung LED TV that I bought just over 6 months ago. It worked fine two days ago. Now when I try to turn it on, the screen flashes to gray then back to black and never comes on. I've unplugged it and plugged it back in, checked all cables, and tried to power on with both the remote and the TV itself. Nothing works. Anyone else have this problem?