TV power cycles if HTPC is not playing video

I’m trying to setup an old skylake nuc (i3) as an HTPC. I’ve installed Ubuntu 18.04. Intel accelerated video seems to be working.

My problem is that if I am not playing a video, the TV will power cycle about every 30-60 seconds. If I play a video it all works great. I can watch an hour of video and it’s all fine. I can even start a youtube video, mute the audio from it, switch tabs, and throw it on a different desktop and it’ll all work great.

So far I’ve tried:

  • A different HDMI cable
  • A different HDMI port on the TV (the one the roku uses, and it never had problems, so that port has to be good)
  • Telling Gnome not to do any screen blanking or suspend (although 60s isn’t long enough to hit any timeout anyway)
  • Running caffeine (no effect)
  • Setting the powersave governor to performance, no effect (except that it never clocks down).
  • Booting with i915.enable_psr=0 - I thought for sure this was it, but no dice.
  • Turning video acceleration off in xorg.conf (although I’m not entirely sure I did that right)
  • Turning on guc and huc firmware loading (not sure exactly that is, but no effect).
  • Verified I have the microcode package installed for intel (I’m just trusting ubuntu that installing that package causes them to load it on boot)

Any ideas on what else I can do? You kind of can log in and run a youtube video real quick and leave it playing while you look for whatever you actually wanted to watch, but it’s pretty irritating.

I’m pretty confident it’s not the TV (which is a vizio, so kind of a cheap POS) because:

  • It never has any problem like this when dealing with the roku
  • If you’re playing video all is well, so clearly it’s not overheating or running out of power

Thanks in advance for any ideas!

Try to find a way to disable HDMI CEC from either the NUC or the TV. Either that or don’t pass audio through the HDMI, because cheaper TVs and monitors don’t like audio over HDMI.

Worst comes to worse, use a DisplayPort 1.2 to HDMI 2.0 active converter.

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I’m gonna double check, but I believe I shutoff CEC on the TV already.

I really need to pass audio through the TV, because I’ve also got a ROKU attached.

This makes me wonder, maybe it’s not about video maybe it’s about audio. I wonder if I played a nearly inaudible audio file if it would also prevent it from shutting off. I could do something like that and no one would notice.

Vizio is kind of notorious for jank PSUs. I know you said its not doing it with the roku, but it could be something with 4:4:4 signal taking more power than 4:2:0.

Addiitonally I’ve heard of the Vizio remotes being REALLY weird when low on battery. Try hiding the remote and see if the problem continues.

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So I marked @FurryJackman as the solution, but it’s not exactly it.

I’m sure I turned CEC off. But I went back in and checked and it was on. So I turned it off. And it was better, I got more like 5 minutes. Then it did it again, and CEC was back on. Went through a couple cycles of this before I decided I’m not insane.

So I broke down and decided to connect the thing to a network to run updates. Tried wifi, but it just couldn’t quite make it (my little iphone se was having no trouble in the same room, so I’m not sure if that’s a range or software issue). So I dropped a temporary ethernet cable.

After the update it seems better. I verified it had kept CEC off, and then I logged into the HTPC and fiddled for about 10 minutes without any screen blanking.

So, I think I got it :crossed_fingers:

Silly me, blaming intel Linux idiosyncracies when of course it’s the crappy Vizio. I knew Vizio’s were bad, but there’s not a lot of choice in the 40" TV market and that’s the biggest we could fit in the space; so I bought one anyway. I knew better, and I bought one anyway.

I think the problem with this theory is that the TV will run indefinitely on the linux system if I’m playing a video. The blanking problem only happened if I didn’t have a video playing (so browsing the web, editing some files in the terminal, running updates, etc).

Heh, When TVs get too advanced, the firmware and operating system is the first point of failure on a TV.