I'm very sorry for any inconvenience this may have caused you. I suspect that it is a service issue. Since you've already called in, how about you come through one of our social media channels instead. Here's the thread where you can get details on setting that up: http://forums.cnet.com/7723-13973_102-542437/service-issues-click-here-for-help/
I have a Samsung TV LN46A650 which was connected to a PC. It had recycled itself a few times. At that time I thought this was an issue with the video card getting too hot and I shutdown the computer and after sometime the problem would be gone. This issue would happen very rarely. However, I connected it to a Roku box about a month ago and it has started turning on and off more frequently. I thought it was the capacitor problem that people were talking about and called Samsung. They sent a technician who said that all my capacitors were fine. he replaced it anyway but still my TV keeps giving me the same problem. I tried connecting my laptop to the TV and that has the same problem. It won't even work when connected to an aerial. Sometimes it will work for sometime and then randomly switch on and off. Sometimes it will make a jarring sound and then turn off. I checked the power supply with a multimeter and tried HDMI and AV output ports and also different power supplies same problem. Contacted Samsung about the problem and they said that they will get in touch with me in 2 days and this was last Thursday and no one has got in touch with me.