Apple TV Volume control not working properly VIA eARC.

It sounds like you’re taking the right steps for HDMI CEC control…

@Anthony wrote:

[…]

volume up is working but volume down will not work.

This sort of partial function usually indicates the remote needs to be reset, then paired again with the ATV4K.

[…]

this option also allows for control of volume via iOS Apple TV remote. Choosing any of the IR options results in losing volume control functionality via iOS Apple TV remote

From this, are you confirming that volume up and down (and mute) are working correctly with the iOS remote? If so, that’s another indication that the ATV4K, your TV and soundbar are configured correctly (HDMI CEC functions properly enabled everywhere), and that the Siri Remote needs to be reset.

Trouble steps attempted

reset to factory Soundbar, Apple TV and LG TV

update tvOS to 15.4.1

repair Apple TV remote

unplugged all hdmis and power to all devices.

Make sure to do the full reset of the remote as described in here: If your Apple TV remote isn't working - Apple Support. For quick reference:

1. Point your remote at your Apple TV. Make sure that the remote is about three inches from the Apple TV. 
2. Press and hold Back  (or Menu) and Volume Up  for five seconds.
3. If asked, place your remote on top of Apple TV to complete pairing.

@Anthony wrote:

That unfortunately, did not work. Also the function is also available in the iOS Apple TV remote via the control center but even through the control center the function for volume down does not work only volume up. I also attempted to update the firmware of the remote with no luck - connected to power over night and firmware stayed the same not sure if it is on the latest firmware or if the update is not pushing through.

Well that’s too bad… Since the volume control issue is consistent using both the Siri Remote and the iOS remote, this points back to soundbar or TV settings.

All I can suggest is that you take a closer look at, and verify, all of the sometimes-elusive HDMI CEC-related settings on both the TV (LG calls it SimpLink) and the soundbar (Samsung calls it Anynet+ :-). I’ve seen some devices break CEC into several options... On the ATV4K it’s just Settings > Remotes and Devices > HOME THEATER CONTROL: Control TVs and Receivers = On (I’m pretty sure you’ve got this already:-).

Also, have you tried connecting the ATV4K to an HDMI input on the Q950a rather than the TV? I gather it passes HDR and Dolby Vision correctly (even though Samsung doesn’t really do Dolby Vision?).

All else fails, give Apple Support a call… and here’s their recommended reading: If you can't control your TV or receiver with your Apple TV Remote - Apple Support.

Yes I contacted Apple and have been going back and forth for 2 days.

An hour on the phone Apple have advised me a couple things,

1. eARC is a beta feature and that these sorts of issues are expected.

2. Multiple suggestions to contact Samsung or Sony despite advising the support rep that there are other users with LG and Samsung TV’s experiencing the same issue.

3. Based on Apple support documentation I should definitely have something called “audio return channel” under Settings > Video and Audio > Audio Output. I was directed to this link: Use HDMI ARC or eARC with your Apple TV 4K (2nd generation) – Apple Support (AU) - The support rep made references to the screenshot in the support article which shows a "audio return channel". On my Sony 75" X9500 the sound output option is set to "audio system" and on my Apple TV's audio output, the default audio output is simply "Receiver Speakers".

4. After testing multiple configurations, as well as advising the rep that I could control the soundbar’s volume with an old android tv, and that my Sony remote could control the sound bar with the Sony remote control the rep eventually gave up and advised me that I would have to visit the Apple store with my Apple TV AND my sound bar so that they would be able to test it.

To be honest I don’t see myself dismantling my entire setup and lugging my sound bar to the Apple store.

I got the exact same issue with the Samsung Q900A Soundbar and the Samsung Q95A TV. Tried with eARC, ARC, directly connected to the soundbar, connected via TV.

resetting the remote did not help unfortunately. Reset the ATV, Soundbar and TV already but no luck.

did you find a solution in the meantime?

I’ve got the same issue. Sony 75” X9500H and a Samsung Q870A. I am able to increase the volume on my sound bar using the ATV4K remote, and with my iPhone via the remote app, but I am unable to decrease the volume.

I’ve updated firmware on my Apple TV, sound bar, and television.

Plugging my ATV4K into the sound bar or the TV directly gives me the same result.

I was happily using my 1st gen Apple TV 4K and only upgraded to the 2nd gen for eARC support. The only feature I’m interested in is controlling my sound bar’s volume via software rather than learning the remote and using IR.

I also want to note that the mute and unmute function on the ATV4K remote works as well. The ONLY thing that doesn’t want to work is decreasing volume.

Really disappointing.

It sounds to me that this is an issue with Apple TV and Samsung Soundbars. I have the same issue with a LG 77 CX OLED TV and Samsung QL-800 Soundbar. The standard Apple TV remote and iPhone/Siri remotes behave the same way. I’ve tried everything mentioned in this forum and I cannot get it to work. Including power cycling everything.

At this point I assume Apple will need to update something in the Apple TV as that appears to me to be the only variable in my setup that could have changed recently (Apple TV is set to auto-install updates and both my TV and Soundbar haven’t had their software or firmware updated since at least last year). Everything worked fine until a night or two ago. I noticed I had to manually install tvOS 15.5 today because it still hasn’t auto-installed it. I can confirm that tvOS 15.5 did not resolve this issue. Is there a way we can report this issue to Apple?

mikereed36 wrote:

It sounds to me that this is an issue with Apple TV and Samsung Soundbars. I have the same issue with a LG 77 CX OLED TV and Samsung QL-800 Soundbar. The standard Apple TV remote and iPhone/Siri remotes behave the same way. I’ve tried everything mentioned in this forum and I cannot get it to work. Including power cycling everything.

At this point I assume Apple will need to update something in the Apple TV as that appears to me to be the only variable in my setup that could have changed recently (Apple TV is set to auto-install updates and both my TV and Soundbar haven’t had their software or firmware updated since at least last year). Everything worked fine until a night or two ago. I noticed I had to manually install tvOS 15.5 today because it still hasn’t auto-installed it. I can confirm that tvOS 15.5 did not resolve this issue. Is there a way we can report this issue to Apple?

Apple's implementation of CEC volume control is fine. I've never had any problem with my ATV4K connected to a Sony soundbar & LG TV. I can't recall ever seeing a posting here about intermittent volume control issues that didn't involve Samsung "Anynet+" (aka Samsung's brand name for CEC).

A simple Internet search reveals descriptions of this Samsung soundbar problem with no references to Apple TV devices. Here's one example on Samsung's community site.

This is a completely different issue. We are able to up the volume, mute the sound, but can’t lower the volume. It did work perfectly until tvOS 15.3 or .4 came out. No updates installed on the soundbar in the meantime

I agree. The Samsung article from bgmeek was not helpful nor relevant. I believe the issue started with tvOS 15.4 (and 15.5 didn’t fix it). It’s not an intermittent issue, it just stopped working after a Apple TV software update.

Sorry folks... I had found the thread via Google search and I suppose it was referencing this post on the second page that includes the following:

Oh my god it's not just me! Did you ever find a solution for this? The CEC soundbar control mostly works - volume up always works, but volume down seems to get "stuck" at a random level....you can volume up from there but volume down always gets stuck at that same level until mute or restart. I'm seeing it on a Sony TV also (xbr-x930e) and a Samsung HW-M550. 

...given that this post is from 12-23-2019, I don't think that tvOS 15.4 is to blame. Does the problem go away for a while after a soundbar restart?

Anyway, I fear the odds are high that we are talking of more than one problem in more than one company's product(s). I never pretend that the ATV devices are bug free, but from what I've read in this thread describing issues seen elsewhere, it seems this "can't turn down the volume" issue is more common on Samsung soundbars.

It's up to Samsung and Apple to workout where the bugs are, but you know this forum would contain WAY more complaints over the last few months if they had recently introduced such a fundemental bug where turning down volume via CEC is broken.

The problem is persistent and doesn’t go away after a restart unfortunately. Volume is not stuck on volume up at any level. Everything is working fine but volume down is not.

I really don’t like Samsung and I tend to blame them first, but as I kept my soundbar from going online and updating the issue has to be on the Apple side. Or it is something those two companies have to figure out together. Still it has been working for months until there was a tvOS update.

I just wanted to follow up on this forum with an update. Long story short: I updated the firmware on my Samsung HW-Q800A Soundbar, installed two software updates (one was a major version update) in my LG CX TV and updated to tvOS 15.5.1….still no luck. These updated too me close to an hour (I had to reconfigure all my past settings on my tv). I was convinced when I saw version 15.5.1 that Apple for sure patched this issue, but nope! Any suggestions on how the heck we can get Apple’s attention on fixing this? I am still convinced the issue lies with Apple.

Is there a way I can possibly reset the learned devices (TV and Soundbar) and force the Apple TV to relearn the remotes? I am trying to do that now but it’s not detecting anything from both my tv and sound bar remote and I’m guessing it’s because it had already learned these?

Normal HDMI devices reset their bindings when unplugging the HDMI cable while both devices are active, but I don't think this will help. I got a second ATV (4K 1st Gen) connected to a Sony soundbar and TV and switched it with my main ATV (4k 2nd Gen). Same issue, even though that 1st Gen ATV has never seen my Samsung setup.

Anyone still got support on their ATV and can give Apple a support call about this issue?

That would be awesome! If you could please reply to this forum when you speak to them we would all greatly appreciate it. Even if it’s a bug they will eventually patch with a software update. I have an Apple TV 4K 2nd Generation that I bought when it first came out last summer, so I no longer have complimentary tech support since it’s been past 90 days.

Thank you in advance for your help!