There's a celebration going on!!!!! My model has a black plastic shield running almost the entire length of my TV under the Bezel. I couldn't see the small LED's you referred to, the Black shield is this.....the Power Light in located in it....about 8' in from the right. So I covered the entire Black Shield.....and....the Remote's light came on. If you only knew how frustrating it was to know I had seen the remote Lights come on but didn't know why or how....just sometimes the lights would come on. And, even more frustrating to have SamSung's tech Support tell me I had to be seeing things because the Remote for my model didn't have Key backlighting. Its is a shame that such a well sold TV has such a Poor technical support unit; I get the feeling the agents simply refer to the TV's Manual and if the answer is there you'll get an answer, if not, you go away very disappointed.
So now I have Cardboard covering the entire Black shield, including the Power light (and with all that covered all the Remote Commands work and its Keys light up. Now I will need to gradually uncover portions of the shield to find the exact Hot spot...and it may well be in the area you described but like I wrote, I didn't see any small LED receptors. and, by the Way, I do have the ECO setting all to off. Its ridiculous at Factory Defaults how dark the picture went in a dark room, I know there's an adjustment so it doesn't get as dark, but at the factory default no one can comfortably watch and enjoy a show....so they all went off.
The area that causes me some concern is the lip sync; sometimes I see the characters on the Screen lips not in sync with the Audio....but I am not sure it isn't more my Cable Box as it is the TV. I have not tried playing with the Digital audio setting which I have been told would resolve the issue....it could also be an HDMI issue from the Cable Box to the TV. I basically have the TV set as it came out of the Box with the exception of turning off all the ECO settings....and I love the Picture.
Thanks; you don't know how much you have made my Day....I have said, the Best technical Support comes from people who already have the Product and experienced the issued and resolved it.......