Well that sure is obvious that you didn't understand what I said, so perhaps relax and re-read it. Of course I didn't expect bOS to do anything with the controller off, that's the point. And obviously it was related to the firmware, because I had done it numerous times already and the stock Bitmain firmware never did that. It also didn't do it again on my surviving board, after I went back to the stock firmware. That's the thing though, brainless miners can't hurt themselves. Until then, I have never had a board heat itself up, without a brain to tell it to do so. That would be very bad if they did. It would be a massive design flaw if the boards kept heating, since if your controller died and the fans went off, the boards would fry themselves and possibly catch fire.

And yes, I know all about turning on the controller last. I've been doing that for years too, since the KnCs are the same way. Actually, the old (Jun 2016 & Jan 2017 - V0.1) S9 Installation Guide is what I originally saw and saved, talking about using more than one PSU, so sorry, but that's wrong. They specifically mention not to power one board with separate PSUs, which makes perfect sense. And they mention powering the controller last.

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