Thanks for the in-depth analysis and recommendations, David!
An extra note: in last night’s new episode, no black screen (in HDR), and no idea why it unless they heard the complaints and adjusted to HDR10…
I also watched last night’s episode without issues. More generally, I will look at Dave’s advice regarding TV cables as I am getting an occasional brief fogginess with the video. I hadn’t realised the updates to the “quality” of streaming services might make old cables redundant.
That’s unlikely to be cables. I’ve seen total dropouts (black screens) and artifacts (regions where the color is flat-out wrong, like green or magenta lines across the screen) caused by bad cables.
Fogginess (fuzziness?), in my experience is usually caused by network glitches. Reduced network bandwidth causes the player and server to renegotiate to a lower-bandwidth stream, which often looks fuzzy, or pixelated or may result in dropped frames (jerky motion). Until more bandwidth becomes available and then they negotiate back up again.
It can also be caused by your device failing to complete HDCP negotiation. Some devices respond to this by degrading the picture quality (and other devices just refuse to play video altogether). Which could be caused by cables that are losing signal, but I would expect you to see that kind of degradation all the time, not just for certain programs or at certain times of day.
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Well, I started watching Down Cemetery Road this week – and I’m encountering the same intermittent black screens (but with audio still working) problem on my Apple TV (device). Sometimes only for a couple of seconds; sometimes for maybe up to 10 seconds.
And, like others on this thread, I’d had the problem before with Slow Horses as well. (I can’t think of any other shows it’s occurred on.)
However, I found a repeatable and reliable way to get rid of the “blackouts”: switch off Dolby Vision. Specifically: go into Apple TV’s Settings app, and under Video and Audio, change Format from 4K Dolby Vision (60 Hz) to 4K HDR (60 Hz). (4K SDR (60 Hz) also works.)
I know this is different than some of the other solutions on this thread; someone said they fixed the problem by disabling HDR. So I’m wondering if the fixes are dependent on the TV and Apple TV hardware. Here’s what I have:
- Apple TV 4K 128GB Ethernet (2022 4K 3rd Gen); latest tvOS 26.x version. Connected directly to our cable internet modem via Ethernet.
- LG 48” Class A1 OLED 4K UHD Smart TV (Circa 2021. Also, not connected to the internet, so happily it’s a Dumb TV.)
- TV and Apple TV connected via HDMI cables.
Anyway, another data point. I’m glad to have a solution for my A/V setup – at least, whenever there’s an adaptation of a Mick Herron novel on. 
This sounds like your cables may not be up to the bandwidth required. DolbyVision is a 12-bit-per-pixel (per channel) HDR format. “Plain” HDR is HDR10 (10 bits per pixel). And SDR is 8 bits per pixel.
So at 4K (3840x2160) 60 Hz, we’re looking at about 8.3 M pixels per frame or about 500 M pixels per second. At SDR, that’s 24 bits per pixel (8 per pixel per channel) or about 12 Gbit/s. At HDR 10, that’s 30 bits per pixel or about 15 Gbit/s. At 12-bit HDR (like DolbyVision) that’s 36 bits per pixel or about 18 Gbit/s. All for the image - add a bit more for audio.
- Standard HDMI cables are certified to 2.2 Gbit/s - not even close to what this signal requires
- High Speed HDMI cables are certified to 10.2 Gbit/s - which also can’t handle it
- Premium High Speed cables are certified to 18 Gbit/s
- These can handle 4K at SDR and HDR10
- These are just at the threshold of 4K with 12-bit HDR. Add the bandwidth of audio, and the signal is probably over the limit. Which would explain the intermittent dropouts.
- Ultra High Speed cables are certified to 48 Gbit/s
- Ultra96 cables are certified to 96 Gbit/s
If you are using Premium High Speed (or lower-speed or uncertified) cables, consider swapping them for Ultra High Speed or Ultra96 cables. That might solve your problem.
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I needed to get a new HDMI cable anyway, so I ordered a Monoprice 48 Gbps Ultra-High Speed cable from Amazon. When it arrived, I swapped it out with my existing HDMI cable; then shut off and restarted the TV, and also restarted the Apple TV, just to make sure things had reset. (The Apple TV’s video format is back to being 4K Dolby Vision (60 Hz).)
Unfortunately, the Ultra High Speed cable doesn’t appear to make a difference. Down Cemetery Road still blacked out in the same places it previously had, with the new cable.
Still, glad I tried it – that’s another data point to the whole mystery.
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Curiouser and curiouser!
Given the range of hardware and different settings experiencing the issue it is looking more and more like a bug in tvOS. Particularly as the brief blackouts started without any changes to my system, other than a tvOS update.
In desperation I might try resetting the ATV to factory settings.
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Sorry to sound like the next thing to The IT Crowd, but could you please tell us which model of Apple TV you have, what firmware version it’s running on, and which version of tvOS? Thanks.
Ah, yet another fine way of confusing the consumer. I wonder why the consortium couldn’t have instituted a numbering scheme that would have been more decipherable than super, super duper, hyper super duper, and so on.
Good suggestion. Here’s the info:
- Apple TV 4K (3rd Gen, 2022, 128 GB storage), Model A2843, MN893LL/A
- tvOS version 26.5
- Firmware version 23L471
Thanks.
Don’t know if you checked Apple’s About 4K, HDR, HDR10+, and Dolby Vision on your Apple TV 4K document, but section 2 (“Use the correct HDMI input and settings” under “Get the best picture”) notes that some TVs, “only support HDR on HDMI input 2 or HDMI input 3. Check your TV user guide to identify which inputs support 4K and HDR.”
Would HDMI 1 (which is marked as ARC) be as good as HDMI 2 or 3 to take the signal?
My problem (in Australia) is some free to air tv channels that have apps won’t play the content on some of them (not all), even though the one minute station promo does play, but then it just shows the spinning cog!
I’ll test all the HDMI slots in tv in a day or so.
Yes, but if your TV doesn’t support it on the chosen port, you won’t get HDR at all. Either the Apple TV will refuse to use it or you’ll get a permanent black screen. You shouldn’t see intermittent dropouts.
And certainly not limited to specific scenes in specific movies.
Consult your TV’s owner’s manual. If different ports have different capabilities, it should tell you all about it. Similarly, if a port might need to be configured for certain capabilities.
ARC is an HDMI feature where a TV can transmit audio out a port. The idea is that you might have a stereo/surround receiver handling all your audio. If the TV is presenting video from an interface different from the receiver (e.g., its tuner, or streaming apps, or a different input), it can send the audio to the receiver instead of using its own speakers.
I use this all the time in my home setup. Most of my gear (game consoles, satellite receiver (when I had service), VCR, audio equipment, etc.) is connected to the receiver, which in turn sends video to the TV. But my Apple TV and Blu-Ray player are connected directly to the TV, since they support DolbyVision but my receiver does not. When I play content from those devices, the TV forwards the audio to the receiver via ARC.
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In order to test various possibilities for my issue with black screens I decided to experiment with a second, older ATV.
I tried to reset the second ATV to factory settings so it would be on a much older tvOS. Unfortunately I had One Home activated which (it turns out) meant the device automatically installed the latest tvOS, despite my selecting not to update the OS at the start of the process.
So I will try again tomorrow, after disabling One Home, if I can work out how.
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It appears my problem relates to the age of the TV itself. It is a 75 inch 2017 (base) model which has 4 HDMI ports 2.0. The problem seems to be none of the ports handle the modern requirements of HDCP. The “handshake” fails after a minute or so, and drops the video though the audio keeps working.
After several minutes this message pops up.
This video can’t be played.
It looks like your HDMI cable or connection doesn’t support HDCP, which is required to play this type of video. Try reconnecting the HDMI cable from Apple TV to your TV, and play this video again.
Despite trying everything suggested (including ChatGPT) it fails to work for streaming free to air via AppleTV apps, even though every movie on Apple TV+ works perfectly.
Solution: buy a modern tv with modern HDCP (2.3) ports 
Edited: Fixed HDCP typo from 2.4 to 2.3. (Thanks JimBlock).
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Probably just a typo, but to avoid confusing anyone looking for a new TV, the latest version of HDCP is 2.3.
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Nope - there seems to be no way to reset an Apple TV and have it boot to a tvOS earlier than 26.5. This is partly because, I suspect, it demands to be connected to the internet via wifi and be “registered” with Apple.
So back to playing with cables and ATV/TV settings…
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Jumping in late here but I have also had intermittent black screens with various shows. I have:
- an AppleTV HD
- tvOS is 26.5 (I think)
- TV is a Samsung 5500, which is several years old but works fine
The blackouts last a few seconds and then the show resumes. Happens rarely but it is not limited to one show.