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So I recently invested in the LG OLED55C7P, which is gorgeous. I can now run my individual HDMI sources (Cable, Apple TV 4K, Xbox One 😵 to the TV, and audio out through optical to the playbar and beyond. All was good for video and sound - 5.1 for each source, and I didn't need a splitter (I used the Octava before, with my old TV).



In reading about Dolby Vision, etc., I saw that Apple recommended the Belkin Ultra High Speed HDMI cable. I saw conflicting opinions, but I wanted to use the best that I could, so I bought the cable and stuck it between the Apple TV and the TV. Boom - I started getting the 'Unsupported Audio' error in Sonos. I recycled power for everything, tweaked the TV audio output settings, tweaked the Apple TV audio output settings, and no luck. So, I swapped the good old HDMI cable back in, and life is fine.



So my question is - does anyone have perspective on why this cable, which I'd assume would be backward compatible, would have issues? The TV (2017 model) can pass through Dolby Digital/DTS multichannel via Optical, and it works fine with the non-Belkin cable between the Apple TV and it. I'm still getting Dolby Vision via the Apple TV with the old cable, so I don't seem to have lost anything, but it didn't make sense to me, so I figured I'd ask the experts!



Thanks in advance for any thoughts.
Apple TV 4k, cable set top box, LG OLED65C7P, Playbar, Sub, and two play:1 surrounds connected via optical to tv and hdmi to devices. The set top cable box typically work fine. The apple tv navigational clicks and certain apps work fine with the sound, but I run into issues playing shows in Netflix or iTunes movies previews, etc. Sometimes it carries over to the cable box if I change inputs back while the audio is out on the Apple TV. Changing back and forth doesn't always work for me...so frustrating....thank you guys for posting your troubleshooting and results
I received the optical splitter today. J-tech extractor should come tomorrow. I've been running the pixel compensation slide cycles since football ended yesterday. Figured I might as well earn some progress there in the meantime 🙂.
What are the pixel compensation slide cycles?
It's running full-screen slides of red, yellow, black, blue, grey, etc. You do it for 4 hours at a time, at which point the LG will do a compensation cycle (pixel refresh) when you turn the set off. The AVS forum folks swear by them for new sets,
Question for you both....which HDMI port are you using that’s giving you problems? I was digging around and noticed ARC was a common denominator for a bunch of similar problems. I switched my Apple TV from HDMI 2 (ARC) to HDMI 3 and apparently my problem went away...not extensively tested but content for audio that has never worked is working now
Very interesting. I feel dumb for not having thought about this. The input that I have to cycle through in order to re-gain audio is HDMI 2 (even though I'm using optical out to my Playbar), which happens to be my Xbox. That's the one input that has never had trouble. The Webos audio menu doesn't differentiate between ARC and Optical (it's the combo choice). You're right, but that has to have something to do with it. I'm not relying on ARC for anything right now, as I don't have a receiver in the middle, but that's got to be an important part of the equation here.
Interesting comment Moosh and even more interesting that it seems to have solved your problems. Funnily enough, I did think of it yesterday, as it just so happens my Nvidia Shield is in the HDMI 2 port. However, I switched it to HDMI 1 and 3, tried it and it worked for a while then cut out again after as usual.



I ordered the newer version of the Nvidia Shield which arrives today. I will re-test the HDMI theory and see if the same happens. My HDMI Audio Extractor has also just arrived so I am hoping that will be the complete solution regardless. I would rather stay away from the pass through of the TV as it has been unreliable from the get go. Everything running through optical is preferred.
Ok - so, with the extractor between the Apple TV 4K and the TV (optical out to soundbar via the optical splitter), I have one improvement: the sub-second audio delay/sync issue is finally gone. I'd tried everything to fix that to no avail.



However, I still have the issue of having to cycle through HDMI 2 (X1X) when switching to or from HDMI 1 (Cable) or 3 (Apple TV) or else I lose audio.
Damn. My extractor didn’t work either. It passed the video through perfect but sound was a no go.



What’s the delay issue that was fixed?



I tried playing with the inputs paying attention to what Moosh said but it’s made no difference. It’s a very strange issue.



I have moved the inputs around as follows;



HDMI 1 - Nvidia Shield (Optical from TV into splitter)

HDMI 2 - Virgin (Optical into splitter)

HDMI 3 - PS4 Pro (Optical into splitter)



If I’m watching the Shield the 5.1 works, then if I switch to the Virgin and back the 5.1 doesn’t work yet stereo does. I think have to switch through HDMI 3 and back to HDMI 1 to get 5.1 to work again. So odd and no explanation. Even tried not using HDMI 2 all together but no luck.
Shoot, that stinks. The delay issue was the audio/video sync (video ahead of audio) - it's a notorious issue for Apple TV 4K + LG OLED users. Something happens at the TV level which is insurmountable without lowering settings to stereo (2.1), even if you use the native LG Audio sync settings.
Okay so I did some reading last night and found a couple of threads on the AV forums. Basically this is 100% a firmware issue with the TV. We’ll have to wait and see if it gets fixed.



I’m annoyed that my extractor didn’t work as would have preferred full optical set up but it may also be the HDMI issue of the TV stopping this from working.



I’m going to call LG today to report. More people who report it the better.
LG said they are aware of the issue but have ‘no information’ regarding a fix timescale.
Ugh - thank you
Just a quick update. I replaced my TV yesterday for dead pixel issues. I received a new November 2017 build. Previous TV was August 2017. The firmware pre-installed was 3.60 something. The 5.1 works perfectly on all sources with no issues. Confirms it is 100% a firmware issue. I just wont update until they fix it.
Ha - that's interesting. It's unfortunate that you had the pixel issue, but I'm glad to hear that the audio problem is resolved.
Checking back in and reading through your comments and I can reaffirm what you guys have already said. What I thought had fixed my problem turned out actually just being a temporary workaround that you already identified for cycling through the inputs...I go from my Apple TV input (HDMI 3) to the empty slot (HDMI 2) and back to Apple TV and the sound works again. Everything I was reading also supports it being a firmware issue. My unit was purchased in late November and I had taken the latest firmware. Sorry to hear about the dead pixel, happy to read though that you were able to get it replaced. I'm going to call LG and +1 the bug.
Update guys! Firmware 4.70.36 has been released in the US with notes:



To improve OLED model Dolby no audio issue when switching HDMI input



It's not out in the UK yet so I can't test. Let me know if it fully fixes this issue! If it does i'm slightly annoyed I brought the optical slitter and multiple optical cables but a least its running direct.
Just installed it and it seems to be working fine..problem solved.
Yeah
Unrelated question, but asking because you guys have the same setup as me. Do you have any issues with no video on ultra hd Netflix on the Apple 4K tv? I upgraded Netflix and only get audio...
Unrelated question, but asking because you guys have the same setup as me. Do you have any issues with no video on ultra hd Netflix on the Apple 4K tv? I upgraded Netflix and only get audio...
Unrelated question, but asking because you guys have the same setup as me. Do you have any issues with no video on ultra hd Netflix on the Apple 4K tv? I upgraded Netflix and only get audio...
Unrelated question, but asking because you guys have the same setup as me. Do you have any issues with no video on ultra hd Netflix on the Apple 4K tv? I upgraded Netflix and only get audio...
Unrelated question, but asking because you guys have the same setup as me. Do you have any issues with no video on ultra hd Netflix on the Apple 4K tv? I upgraded Netflix and only get audio...