Apple TV 4K flashing/signal loss only when set to 4K

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Level 1

10 points

Apple TV 4K flashing/signal loss only when set to 4K

When I play 4K programming on my Apple TV 4K to my LG OLED C9, it will flash to a black screen, maybe once ever 30-60 seconds, go quiet, and then restore the picture and the Dolby vision or HDR logo will appear at the top of the screen. This happens on Prime Video, Netflix, and other 4K apps.

it’s the worst if the Apple TV is set to 4K Dolby vision. It’s a little better, but still happens if it is set to 4K HDR.

if I set it to 1080 Dolby vision or 1080 HDR, the problem goes away.

I’ve reset/restored the Apple TV.

I’ve tried multiple premium cables, including what Apple recommends and the mono price cables.

if I use the built in smart tv on the LG, it streams 4K HDR with no issue.

I’ve turned content match on and off.

I’ve tried different HDMI ports.

I’ve updated both devices.

Any other ideas? It’s annoying to have the newest Apple TV and more and more 4K content that I have to watch in 1080.

This has been going on for months and I haven’t found any helpful answer online.

Apple TV 4K, tvOS 15

Posted on Apr 7, 2022 8:21 AM

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Answer 1

Top-ranking reply

bgmeek

Level 4

1,237 points

Apr 7, 2022 11:55 AM in response to JohnB5656

Did you by any chance neglect to enable "ultra deep color" (or whatever LG refers to enhanced HDR) for the specific HDMI port that your ATV4K is connected to? I believe it's in your TV's Settings > Picture > Additional Settings > HDMI Ultra HD Deep Color > [enable for the correct/connected HDMI port]. I have a different LG model than you and I've shared the structure I see.

This setting is sort of hidden in a different place than the HDMI CEC / auto configure stuff under Connections.

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Answer 2

rkaufmann87

Level 10

148,440 points

Apr 7, 2022 8:45 AM in response to JohnB5656

You may have a signal strength issue where the Apple TV is located in your home. If it is connected via Wi-Fi please first try the following:

Unplug the modem from its power source for 2-3 minutes and then restart.
Unplug the router from its power source for 2-3 minutes and then restart.
Unplug the Apple TV from its power source for 2-3 minutes and then restart and retest system.

If the above steps show no improvement, please get a tool such as iStumbler for measuring signal strength and see what the Wi-Fi signal's strength is where the Apple TV is located.

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Answer 3

rkaufmann87

Level 10

148,440 points

Apr 7, 2022 11:50 AM in response to JohnB5656

If you are hard wired then again I would unplug and restart the modem, router and Apple TV as instructed earlier.

If the problem persists, then try your HDMI connection, first ensure it is fully plugged in by removing it on both ends and re-connecting. If still no luck then try another HDMI cable and ensure you are using at least a 4K capable HDMI cable, they can and do fail on occasion. A cable like Rocketfish™ 4' 4K UltraHD/HDR In-Wall Rated HDMI Cable Black RF-HG04501 - Best Buy would be fine.

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Answer 4

cho88

Level 1

8 points

May 23, 2022 8:31 PM in response to JohnB5656

Did you ever find a solution for this? I am experiencing the same exact symptoms with my Apple TV 4K and LG Oled 65 C1. Specific HDMI ports seems to be worse than others. I know one port did it every minute but a different one seems to do it once or twice a day.

again it is very frustrated and even my Amazon fire tv 4K doesn’t experience it when playing Dolby vision contents.

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Answer 5

JohnB5656 Author

Level 1

10 points

Apr 7, 2022 11:42 AM in response to rkaufmann87

No, it’s not a wifi issue. It’s not a buffering issue. The Apple TV is connected to wired internet. I’ve tried it on wifi as well. But this doesn’t behave anything like an internet issue. It’s a problem between the Apple TV and the LG.

the whole picture goes dark and then it restores but the program has progressed. The content doesn’t pause or bufffer.

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