@Leonard King Hi, I just happended to re-visit this interesting post of yours back from August. It seems that the Samsung sound-bar power-down during idle/no-signal can be set to OFF mode. However, I am unsure if the problem as you described it, is that since the FW upgrade, even with an active sound signal, and eARC active, the Samsung Sound bar was STILL powering down unexpectedly when before it was not? Anyway, here is the link to do that, and you could then enable eARC again, to get back the CEC power-control functionality etc. :
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I don't think that our wish (yours and mine) is as realistic as we think. A television or a monitor is set to one input. Once, you had these "radio buttons" that live on in computer speak: always exactly one button down. If there is no signal on that input, then there is whatever noise.