Apple TV 4K Random HDMI Signal Loss

Well I may have come to a partial solution, partial giving up: if I just choose Reset Video Settings then it selects 4K HDR 4:2:0 and I haven’t had any signal loss passing through my Onkyo receiver in a couple days. I guess I can live without Dolby Vision but it’s still ridiculous that we can’t fully utilize our equipment.

I have an LG 4k Hdr, nothing fancy but the issue is only with apple tv and the way the switching of the frame rate and range is done. If you turn both off, there is no problem, but then the hdr is not working and also the movement is not smooth. I bought another new atv 4k from apple store and with the last stable release it's the same. In the Apple Store it's exactly the same, on those LG Oled screens. It's happening with all apps that require frame/range switching( BBC, My5, Netflix, All4, etc.). Good morning Apple, i'm sure your brilliant software engineers will fix this soon. In the meantime the employees have no idea about this or pretend to, and act like it's something insignifiant.

I think you are correct, the problem is either with the Apple TV 4K hardware or software. I was going to the Apple TV 4K unit and physically unplugging the power cord then reinserting it. I'll try to put it to sleep and wake with the Menu button. I may bring the unit back to Apple since I have not had the problem on other Apple TV 4K units I purchased at the same time.

I have an LG OLED55C7P & and the Apple TV 4K connected to HDMI 1 via the Apple Recommended Belkin 48 GBPS HDMI cable. The LG is on Software version 05.80.15. I have HDMI Ultra Deep Color turned “on” on HDMI port 1.

First off, I’m not experiencing any random HDMI signal loss. On the Apple TV, under video and Audio Settings, I’ve tried both “4K SDR” and “4K Dolby Vision” formats. Both at 60Hz. No random HDMI signal loss when viewing HDR or Dolby Vision content (ie via Netflix, Amazon Prime, Apple purchased movies, etc...).

Other settings on the Apple TV: I have Chroma Set to 4:4:4 and under Match Content, I have both “Match Dynamic Range” and “Match Frame Rate” turned on.

With both Netflix and Prime Video apps, and iTunes purchased movies, I see the HDR or Dolby Vision symbol show in the upper right hand of the TV (depending on the source content) regardless of whether the “format” on the Apple TV is set to “4K SDR” or “4K Dolby Vision”. It appears to switch correctly to match the source content format.

However, I have YouTube TV as my TV service. On the YouTube TV app on the Apple TV, if I have the format on the Apple TV set to “4K Dolby Vision” all shows I watch on YouTube TV are being up converted to Dolby Vision. If instead I have the format on the Apple TV set to “4K SDR” the YouTube App on Apple TV uses my regular 4K SDR format. This is the only app on the Apple TV (that I use) where the format switching is not working correctly (ie given my settings under “Match Content” on the ATV 4K.

If instead I use the LG Smart TV YouTube TV app....the TV detects it’s not Dolby Vision or HDR content and uses my regular 4K SDR settings (ie Bright Room Expert in my case).

To me, it appears that the problem is with the YouTube App. itself....for the ATV 4K (ie versus being a problem with the LG C7 or the Apple TV 4K).

So, if I choose to watch YouTube TV from the App on the Apple TV 4K box, I’m really forced to set the ATV 4K video format to “4K SDR” (instead of Dolby Vision 4K) in order for the YouTube TV app to use my regular 4K SDR settings (ie Bright Room Expert).

Given the above: What am I really missing by just setting the video format on the ATV 4K to “4K SDR” (ie instead of Dolby Vision 4K) and setting the “Match Content” options on the ATV 4K both to “on”? Am I only missing the “icons” (ie the display) on the Apple TV box itself from showing in Dolby Vision? If so, not a bit loss in my view. It seems all of my content is properly switching to the correct format when using the “4K SDR” format setting. Maybe Google (or Apple) can get a fix soon for the ATV 4K apps that are not switching format correctly when the ATV 4K format is set to “Dolby Vision 4K” (ie YouTube TV app for example).

Am I missing something?

Bought the Belkin Ultra HD High Speed HDMI Cable, and changed the setting to Chroma 4:2:2, because the regular HDMI cable on 4:2:0 was not working. I haven't had any problems and the picture looks sharper.

I have been having ongoing problems of various kinds with my ATV4Ks and my LG 65B7A, those mentioned in this thread but also occasional audio skips, TV power turning back on by itself, and ATV complaining about a poor HDMI connection even though it keeps working. I have tried many cables of various lengths and qualities, various HDMI ports, swapped in ATV4Ks from other rooms, and prayer. I have a cause to suggest that I have not seen mentioned here: poor HDMI cable connection to the TV or ATV. I have more or less solved the problem.

My LG TV has soft metal HDMI jacks that bend easily under the pressure of a thick HDMI cable. This may degrade the electrical connection, and I suspect that the ATV4K, the LG TV, or both, or certain software, are sensitive to this. With a small flathead screwdriver, I gently bent the TV's HDMI jack shells inward, and that made a big difference. I have since turned off the TV's SIMPLINK CEC function, and that made it quit turning itself back on. I suspect that also was a cable connection issue, because the problem got worse when the TV was warm.

Manufacturers of expensive TVs should use much better quality jacks, and system/software developers should - if they can, with these high bandwidths - assume that connections will be imperfect. In the meantime, until a new HDMI standard uses locking connectors, we can buy little clamps to lock down our cables, be very gingerly with the jacks, and if necessary bend them back.

I don't know if your issue is quite the same as others. But - you can sign up for the Beta here: https://beta.apple.com/sp/betaprogram/

Please post your results - good or bad.

Some support articles

https://support.apple.com/en-ca/HT208074

https://support.apple.com/en-ca/HT200197

Hello,

I have the same issue with the same TV as you. When I unplug the HDMI on the Apple TV 4k and plug it again, it works for short time. This is a very annoying issue 😟

You have the exact same setup as me.

I didn't experience the issue for the last two weeks. I watch about two hours of tv each day.

Definitely an Apple TV issue I am sure.

I had mine replaced. Still the same issues.

My HDMI cable apparently does not support Dolby vision, so my settings have been on 4K HDR 60 - I have also tried the 4K SDR - and have experienced signal loss on both settings...

My Apple Tv4k just lost signal three times in ten minutes. I’m giving the Echogear HDMI a try...

I got the Echogear 2.1 HDMI yesterday and things worked really well last night. Today, however, I lost signal yet again usIng the new Echogear cable.

This is really frustrating.