I'm not an expert or a TV technician, but the more I read of such problems the more I'm getting convinced that Samsung have no control of the firmware updates that they are injecting in our TVs without or knowledge. If you research more you will find that you're not the first who had to go through multiple visits by a Samsung service tech. Some consumers had this problem with TVs that they have just bought and taken out of the box.
If you have the time, go through the link below. Good luck.
I know this has been discussed before in an older thread, but it seemed to be older model tvs. My UN65F7050 has been power cycling frequently for the past couple of weeks. Samsung has sent out a service tech, he replaced the mentioned cable, as well as the control board. No change in symptons. Should he be looking at the power supply board for symptoms like this? Any help would be appreciated, its getting old waiting between service visits without a tv. This will be his third trip out....