Dolby vision on Apple TV 4K blacking out

This is not the ATV 4K nor is it related to cables, etc.

The issue is with the LG C9 firmware. Around the time your problem started LG updated the firmware to version 05.10.04. Any DV capable device connected through an AVR, such as your Marantz, and then to the LG experiences the problem. I have the same exact issue.

LG is well aware of the problem and is testing/perhaps rolling out a fix already. It MAY be 05.10.15. Best bet is to wait for the update and use HDR as you are doing. I'm doing the same.

Here is a thread that has information in a number of posts. The user "HiFi4Vision" is credible.

https://www.avsforum.com/threads/official-2019-lg-c9-consolidated-info-faq-troubleshooting-firmware-more.3075344/page-80

Suggest you start with post #1583 and read thru.

This is the LG link (assuming you are in the US) where you can see what the current firmware is. You might want to consider turning off automatic updates. I wish I has not turned mine back on.

https://www.lg.com/us/support/product/lg-OLED65C9PUA.AUS

There is also discussion that your AVR might require an update. Oddly enough my Denon got an update a day or two after the initial occurrence. They didn't say what it was for. You may want to check for AVR updates.

Hope this helps. It's complex and difficult to tell what is creating the issue. I was lucky - the LG wanted to do an update - I let it - and immediately after I played a show that was in DV and got the blanking/blacking.

If anyone has an lg tv I figured out the issue. In the sound settings in advanced settings if it’s set to “sound bar mode control” it will cause the tv to blink to a no signal image for a second when switching to Dolby vision. This needs to be set to “tv sound mode share”. This was on an lg c1 with a Klipsch Soundbar using arc. Hopefully this helps someone!

After years of dealing with this with my LG and apple tv 4k (using marantz AVR) I finally found the solution.

Set your apple TV 4k to 4k SDR 60 hertz with range and frame match.

Forgive me if my reasoning is incorrect, but by putting the apple tv into 4k HDR or Dolby vision, you are forcing the metadata to come across as such, and when it has to switch from HDR or Dolby vision to either or, it has a lot of trouble keeping the "handshake." By having the apple TV set to 4k SDR at 60 hertz, whatever the viewing program is it allows a new handshake, and it will match whatever the intended content is being displayed as.

This has worked for me over the last week with no issues what so ever. I have tried every fix up until this point (cable, various settings etc). Hopefully this works for everyone.

I'm not sure what changed, but I had the same issue as well. Ironically, selecting 4k HDR output on the Apple TV corrected the problem. I was worried that this change would no longer allow Dolby Vision content to play in HDR, but my TV says it's displaying Dolby Vision even though the Apple TV doesn't have Dolby Vision selected. I'm assuming this is a bug and will be fixed. One would think the way to view Dolby Vision content would be to enable Dolby Vision.

Equipment: Apply TV 4k (new), LG 77C9, Marantz SR6014, HDMI 2.1 cables

I have been having the same issue as everyone else here and I found my fix. When I connected my Lg C1 I also added a Lg SP2 sound bar with an optical able and atv 4K. I then switched out the optical cable for a hdmi cable as my sound bar has a hdmi arc port and that’s when my tv started flashing to a black screen and coming back with Dolby or HDR in the corner. Like everyone else I changed every cable and setting except the hdmi cable from the sound bar. I just switched my hdmi cable back to the optical cable and have not had a issue since. I’ve tested every stream app Netflix, sling, hbo, STARZ Disney Plus and Prime all without the black screen flashing.

I am on LG C8 as mentioned above. My issue happened only on Apple TV 4K and finally this problem was completely resolved after disabling the Dolby Atmos sound option, switched to surround sound. My visuals are still set to 4K Dolby Vision. Haven’t had a single issue in the last 2 weeks and I watch lots of shows.

Previous attempts of upgrading hsmi cable, TV firmware upgrades, switching to HDR content did not help. I think the problem is sound related. I use optical headset from Sennheiser which didn’t require Dolby atmos but the option was enabled for me in the menu in sound options.

Correct, it isn't rigorous enough. The 4k cable might pass but you might be in a situation where it's choking at the traditional 18gbps cable and that's where the full bandwidth of the 48 comes into play.

• handshake
• colorspace
• audio
• chroma
• resolution
• cec

My strong suspicion is that any hiccup in the transmission of any of those will cause the handshake to stutter and drop signal.

Ideally, it would've stopped by lowering the resolution and sending less data to the tv but not sure the software is not checking to see what the display is capable of.

Trust me, i hate the idea of buying yet more cables but these were cheap amazonbasics 8k / 2.1 HDMI cables (just make sure it's 48gbps) 6ft.

Have been testing all day today and went from drops several drops an hour to no drops all day

edit: and i'm on the most recent update of tvos 15.1

Also (since you have the same tv as mine, but bigger) make sure you have Enhanced 4K HDMI set to on. If you’re on the latest android tv software it’s tap the Home button > Settings > Watching TV > External inputs > HDMI signal formate > Enhanced format. Enable that if you haven’t already and see if it helps.

No, it’s constantly on Dolby vision and match content settings are off. After about 3 seconds from startup the HDMI seems like it disconnects and I get a “no signal” message from the TV. Everything is connected using Amazon monoprice 2.1 cables, but going to try the belkin ones and report back as the comments on the Belkin cables say that this exact issue was solved when switching to them. My suspicion is that even though the cables are certified, it can’t handle the bandwidth needed for Dolby vision at the top end constantly. Also, color balance calibration cannot be done in Dolby vision mode. (For reference my TV is a newer LG MiniLED TV with HDMI 2.1 Ports).

I just swapped out all my cables to Best Buy Rocketfish Ultra HD 4K/8K 48gps. So far everything looks great! No drops at all. Everything looks a little sharper and sounds better. They were $30. Each for a 8ft cable. Perhaps a bit pricy, but if it improves the signal then ok. I’ve had it on all day watching several different football games. Some in 4K. I’ll “keep an eye”on it. Hope to reply in a couple of weeks with good news. Thank you all for your advice. 😀

I just bought a Sony X90J and have it connected to an ATV4K 2021. When set to 4K Dolby Vision the screen would go black every few minutes or so for a split second then come back. Swapped the HDMI cable out with an Amazon Basics High-Speed HDMI Cable (48Gbps, 8K/60Hz ) and that solved the problem. Hope this helps someone else.

I replaced my supposedly good cable with a new high speed cable and my problems with blinking went away, am surprised.

I have an Sony XBR-55X900F and Apple TV 4K 2021, I’m having the same issue. But I just switched HDMI cables to the high speed one that came with my Xbox…so far so good. Also to make a dig at monster cable that’s probably the reason right there, make dang sure it can handle high speeds. Over priced junk.

I have used Monster products for years. Never had any problems. When I got the Sony TV, and the Pioneer, I decided to get all new cables. Monster is now sold at Walmart. 🤔 that was probably my 1st mistake. Everything was ok until the ATV update. Then things got progressively worse. I almost was going to replace the ATV. I was reading all the reviews. Most of them said if you already had the 2018 4K then there really isn’t any reason to upgrade to the 2021 version. My husband suggested replacing the cables, along with the forums. I was going to get the Belkin 4/8K. But Best Buy was out of them. So I got the Rocketfish. It had the HDMI.org logo on it. The only issue I had since my last post was with Disney+ watching Jungle Cruise in 4K. I had to reboot and it was ok after that. Everything else was good. No flickering, or dropouts. This was with all the 4K apps and YouTubeTV.

I have until January 11 to return them if the issue continues. Thanks for your posts.

akramhussain wrote:

Same this is happening to me on an LG TV. Alll cables are 2.1 Ultra High Speed (checked using the HDMI app). Only happens on startup, and then again when the first Dolby vision content is starting.

This sounds different than earlier complaints in this thread... it also sounds like normal behavior when your ATV4K's video format is set to something like 4K HDR and you've got Match Content set to "On" for dynamic range and/or framerate. You're seeing your TV switch modes to accomodate the Dolby Vision content (and back). Why not set the format to 4K Dolby Vision, do the Color Balance calibration, and turn Match Content Off? This will cause the ATV4K to go into Dolby Vision mode on startup and stay there -- adapting all content to your TV's best video mode as best it can.

I've seen some folks complain of visible color issues with some SDR content when the ATV4K is set this way, but if everything looks good on your setup you certainly won't miss the frequent TV mode switches :-).