I am writing this to anyone that may have a roku or similar device. I purchased the MU8500. Same TV just has the curved screen. I found my tv turning on by itself. Here is my set up: Sony str-hd590 4k Receiver into hdmi 4 with arc cec. All devices plugged into receiver. I found that for me the problem lied with my roku streaming stick+. All of the roku devices are always on. They do not have a power switch or button. They stay on all the time. A lot of TV sticks are like this. Since it is always on it is always sending a power signal to my receiver which in turn is sending to my TV. To solve this issue, I purchased myself a 4k HDMI switch. https://www.amazon.com/gp/product/B074Z6Z2NY/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1 This places a barrier between my receiver and my roku. So now I have my Roku, and Xbox One S plugged into this handy little switch. Then the switch is plugged into my receiver. My TV no longer turns itself on. The best part is that I can now use my Samsung remote as my only remote as Samsung intended. This little barrier between the switch and the Receiver make it so that a power signal is not sent to the tv by my Roku. Like I said this will be the same with any streaming device that can't be turned off. Examples include Roku, Chromecast, Amazon TV, etc. So to recap, plug devices into the switch, plug the switch into the receiver, and finally the receiver to the TV. The switch comes with a remote so you can switch between channels, but it is smart enought to switch based on what one is being used. (Most of the time). I can still controll all these devices with my Samsung remote because the switch supports CEC. For some reason this extra step between switch and receiver help better controll on signals coming from streaming devices. As proof that the roku was the problem and not the TV I just unplugged the roku and set everything else up as normal and never had my TV turn on by itself. I thought about how I could keep my roku from doing this to my tv all the time and the switch is the solution. Again to anyone having problems with the tv turning on by itself...If you have a device like a roku, chromecast, or amazon tv, or some type of device that never turns off, this could be the cause of your stress. Hope this helps.
... View more