Apple TV 4K Random HDMI Signal Loss

I read that thread in my search for answers but it wasn't what was causing my problems. Im on a 2018 Vizio M-series, and it worked flawlessly with the apple tv until the update that introduced atmos. I know the addition of atmos has nothing to do with the display flickering but I believe that other included updates impacted the way Dolby vision functioned. As soon as I updated to that firmware, I had constant signal loss. I had no issue forcing the apple tv to output HDR10 but wanted DV. Regardless, a 5 minute update to the newest apple tv beta os has fixed it for me and I have had no issues in weeks.

So I read somewhere that EM interference can sometimes cause the issues we're having. I plugged my Onkyo Receiver into its own power outlet and left the ATV and OLED on a power strip. I also gave the HDMI cables some "breathing room" instead of being all crammed together. It's been a couple days and the worst symptom I've had is just a quick black flash once a day or less. Before it was multiple signal dropouts per hour. It's worth a shot if you're helpless.

I've been skimming this thread every few days to see if a fix was found. Just bought the Apple TV last week. I've tried a lot of the suggestions and was already using the belkin cable, and this fix of going to the beta firmware has worked for me! I really appreciate you adding this info.

Thanks for that info. Also own a 2018 Vizio but E series and it also seems to have problems with Dolby Vision and switching. Switching to the Apple TV can be really slow at times and all I get is a black screen for several seconds so guess it's experiencing signal loss. tvOS 12.1.2 update, 16K5534a is the newest I"m seeing is that the one you are using?

I’ve been watching these threads for months and have given up hope until apple fixes the firm ware. It is disappointing that I have bailed on atoms until the software is fixed but using the optical cable for now allows for blink free viewing.

After confirming that the random signal loss occurs on with the ATV set to 4K Dolby Vision, 4K HDR, and 4K SDR, I have been running the ATV in 1080p Dolby Vision for the last few days and it hasn't lost the signal yet. Why does it have to be like this *sigh*

Yeah works fine at 1080 for me too but what's the point of having a 4K HDR Dolby Vision TV and ATV if you can't take advantage :(

Wish I had another 4K HDR Dolby Vision TV to try since I"m thinking the problem is more on the TV end since Apple TV will actually cause my TV to reboot sometimes which is even worse!

QUESTION: how do I get the TV OS Beta version that several people have mentioned as solving this issue?

CONTEXT

I bought AppleTV 4K in November, 2018, followed by an LG OLED TV (2018 model c8), and then a Samsung N950 soundbar (with a wireless sub-woofer and wireless rear speakers). What I thought would be a great experience has been the exact opposite. I, too, have been experiencing near constant signal loss, effectively rendering AppleTV unwatchable. I’d constantly be losing the picture, and sometimes audio, and often both. Right now, I can’t even get Netflix to start, let alone have it later drop the signal. I would also constantly get the onscreen warning to the effect that the AppleTV was having difficulty maintaining a stable HDMI connection. I’d also get the same answer when I ran the test of the HDMI connection that’s found in the Settings.

I’ve been using new high-speed HDMI cables (18 GB per second, not 48). Up to 48 GB per sec is specified in HDMI 2.1, The HDMI association, or whatever they’re called, said just last week, at CES 2019, that there were no such cables yet on the market. They only had prototypes on display. That said, I just ordered two supposed 48 GBps cables from Amazon (mentioned much earlier in this thread).

I was also convinced - before finding this thread - that it was the Samsung soundbar that was at fault (I had AppleTV connected to an HDMI input on the soundbar, which in turn was connected to the TV via HDMI ARC.). The store where I bought the TV, and soundbar, was also convinced that it was the soundbar that was at fault, so they took it back yesterday, and supplied a SONY HT-ST5000 in its place. I was incredulous to discover last night that the problem with trying to stream content from AppleTV was still present, and still as bad. That’s when I found this thread.

Rather than wait for those new cables, I’d be interested in trying the TV OS Beta that a few people have mentioned earlier, hence my question: how do I get the beta version (in simple language, please!)?

By the way, my new SONY soundbar is eARC capable, but I have that feature turned off, as the TV only has ARC, not eARC. Why do I think that eARC (part of the HDMI 2.1 standard) would solve this issue?

Reply To robnbill,

Thanks for the link. I did indeed sign up for the Apple Beta Testing Program, and downloaded the latest beta of tv OS about an hour ago. While it's early yet, I can say that I was easily able to open Netflix and watch content with no difficulty. The same went for Prime Video and Showtime apps. I have my AppleTV connected to my SONY soundbar, and set the audio/video settings to the most demanding, e.g., Dolby Vision etc. Hopefully, this will continue, but as of now, it seems to have resolved my problems. Too bad I had the store take back my Samsung soundbar (I liked it better than the SONY one I have now). Oh well.

Good news - hopefully it sticks. If I recall tvOS is Beta 4 -- I'd think there may be one more Beta before they release final. I think when Apple released the version that brought in ATMOS - things became dicey. That's my only complaint with Apple - they tend not to let users know of issues with existing versions - so you go out and change cables - sound bars, etc.

The issues seem to be more related to certain products - e.g., Sony Projectors, LG OLED. The problems hit a smaller, narrower, group of users - making issue detection and reporting more complex - and less likely to be found quickly. Not an excuse - just facts - the way I see it. Still hoping Sony will put out a FW update for our projector -- they are difficult to deal with - we see no issue is what they told me! Anyhow, hope your ATV continues to work well with the Beta.

Hi Gilby86, Just wondering what sort of cable length you have between your Apple 4K TV and Sony 850E? Are you using a a/v receiver or just going direct between Apple TV and Sony?

It seemed like my system was getting hit by small lightning bolts for both audio and video. What worked for my system was changing from 2M and 5M 4K cables between the three components to 4' and 12' 8K cables (my working system now has shorter and faster cables -- also note that my system is not currently 4K). I've read but have not confirmed that 15' of cable is a limiting factor. For me the 15' of cable length seems true but I'm trying to confirm it.

I have my Apple TV 4k running with a standard length hdmi cable you get from cable companies to my TV. I have a Sony STR-DG800 a/v receiver with 3.1 surround sound hooked up to the TV. My a/v receiver is not 4k.

Well I just bought an Nvidia Shield to try out bitstreaming TrueHD Atmos and it does work nicely with Plex and MrMC. Unfortunately, the **** random signal loss (display goes black for a second, audio persists) still occurred while the resolution of the Shield was set to 2160p using Plex. MrMC will auto-adjust the system resolution according to the resolution of the video file (which happened to be Game of Thrones in 1080p with TrueHD Atmos). Alas, the signal did not drop while using MrMC because the system resolution dropped to 1080p. So now that I've effectively ruled out the Apple TV and my Onkyo receiver (I recently upgraded models), I suppose the culprit has to be my 2017 LG OLED65C7P.

FWIW, I have been having this problem for months now. Seems to me it was introduced when there was a tvOS update. I have read accounts here that the timing is related to the introduction of atmos. That sounds about right but not sure it has anything to do with atmos.

Anyway, my analysis is this problem has absolutely nothing to do with cables. (Probably the cable guys lurking here trying to drum up business).

What I have found that what works for me temporarily is to reboot the ATV from the settings That seems to clear up the problem for a few hours. Long enough to watch a movie or evening of tv. It is likely a memory leak that is the cause which is definitely a firmware issue that Apple needs to fix. I wish Apple would put the option in the settings somewhere to allow one to schedule a timed reboot. That would not fix the problem but at least it would allow me to avoid having to experience it. Reminds me of the days i had to reboot my router every day ... i expect better from Apple.

On the phone with Apple right now.... 12.1.2 reintroduces the issue again. I had a stable 12.1.1 beta for 3+ weeks with zero drops. I had the auto updates turned off but when I sat down this evening to watch a movie and 5 minutes in, the picture and sound dropped, my heart sank. Somehow it updated and Im now, once again the owner of a $150 paper weight. Please, if using the beta fixed your problem, avoid upgrading at all costs.