Is this just a momentary loss of picture, or does it not come back when it goes off?
If you press the Samsung's MENU button (not a cable or satellite box menu), does the TV's menu also go off?
How long does it take for the picture to come back?
When it goes out, can you tell if the panel is still "primed?" That means if you looked at the screen in a darkened room, does the screen give off a very dim glow even though there is no picture?
OK, then most likely you have an odd issue with the set's Digital Main board, part number BN96-03366A, but that's really just an educated guess.
Since you still have the dark screen glow when this happens, that pretty much rules out the scan drives and power supply, leaving the digital main as the likely suspect. There is an outside chance that the problem could be the panel (the actual screen), but I think that's very unlikely.
Were you thinking of trying to fix this yourself? If you have some electronics experience and feel comfortable changing a board, you should be able top do this. If not, of course, you'll need a tech.
The board isn't too expensive, it's about $130.
Let me know if you need more help, and thanks for using JustAnswer!