Issue with AppleTV 4K not displaying 4K signal

techted

Active Member
I am having an issue with my AppleTV 4K (2021) edition not displaying a 4K signal when I pass it through my Arcam AVR. When connected to my TV via the AVR, the max signal coming out of the box is only 1080p Dolby Vision.

Am pretty sure that when I setup the AppleTV 4k when I bought it back in April 2021, it did output a 4k signal to my TV. A few weeks ago, when I was fiddling around with the settings on the AppleTV, I was surprised to see that the most it would output is only a 1080p Dolby Digital signal.

The hardware:
  • Apple TV 4k (2021 edition, tvOS v15.4.1 19L452, released 14 Mar 2022)
  • 65" LG OLED C9 (OS v05.20.30, released 28 Apr 2022)
  • Arcam 850 AVR
  • JVC N7 projector

This is what I am getting:
1. AppleTV connected direct to the TV (tested all 4 HDMI inputs, deep colour is enabled) >> 4K signal
2. AppleTV connected via the AVR then to the TV >> only 1080 signal
3. Apple TV connected via the AVR then to the projector >> 4K signal

#3 tells me that the AVR isn't the issue. I've also tested other HDMI ports on the AVR which haven't made a difference to the findings.

As I haven't had any hardware changes, and things were working fine before, I am thinking it is either the TV or the Apple TV that is the issue due a recent OS/software update. Both devices has a recent OS update in April and March respectively. Am hoping there are people out there with a similar setup to mine that is exhibiting the same issue and wish to share notes.

Anyone?
 
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next010

Distinguished Member
Set your AppleTV output manually to 4K 60hz SDR.
  • enable match dynamic range and refresh rate.
  • optional - set video output to chroma 420 (default is 444) if it still doesn't play ball.

This will make the ATV auto switch to 4k 23/24Hz SDR/HDR10/DV when playing movies which the AVR should be able to handle.

Your AVR might not be able to handle 60hz DV output if you have left the ATV on its default settings.
 

techted

Active Member
Set your AppleTV output manually to 4K 60hz SDR.
  • enable match dynamic range and refresh rate.
  • optional - set video output to chroma 420 (default is 444) if it still doesn't play ball.

This will make the ATV auto switch to 4k 23/24Hz SDR/HDR10/DV when playing movies which the AVR should be able to handle.

Your AVR might not be able to handle 60hz DV output if you have left the ATV on its default settings.

That is the issue - there is NO OPTION to select a 4K signal manually. Going to the settings on the AppleTV, the highest setting it will give me is 1080p. Does not matter if match setting is on or off. Even if I go to the bottom of the list where one can choose unsupported formats, no 4K options are listed :(

This is only when the AVR is switched to the TV. When it is switched to the projector, it outputs a 4K signal fine >> this tells me that the AVR is able to handle a 4K signal don't you think?

Also when I setup the AppleTV when I got it when it first came out last year, I was able to set it up to my TV via the AVR to output a 4K signal (admittedly, this is an assumption as I am the type to look and fiddle at all the device settings when I get something new and I surely would have been complaining to Apple if I saw this issue in the beginning) >> this tells me there is something recent that caused the problem. As there have been no hardware changes, the only thing I can think of that changed is the software on both the AppleTV and the LG OLED (updated in March & April 2022 respectively).
 
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techted

Active Member
Am trying to figure out if I can roll back the OS on either the LG TV or the Apple TV to a previous version so as to see if it is indeed the OS that is the issue.

Anyone ever done this?
 

gibbletts

Active Member
I'd try connecting it direct to the TV first to rule out the amp also check that you have deep colour enabled for the hdmi port
 

Jase

Distinguished Member
Are the PJ and the TV connected to the AVR at the same time? If so, if you disconnect the PJ from the AVR does that enable 4K on the TV again?
 

techted

Active Member
I'd try connecting it direct to the TV first to rule out the amp also check that you have deep colour enabled for the hdmi port
I mentioned this in my original post above that yes, connecting the AppleTV direct to the TV solved the issue. I did initially think that the AVR was the problem because of this BUT why is it then that when I connect AppleTV>AVR>4K projector the AppleTV outputs a 4K signal fine?
 

techted

Active Member
Are the PJ and the TV connected to the AVR at the same time? If so, if you disconnect the PJ from the AVR does that enable 4K on the TV again?
!!! That worked!!! You win a prize mate!!!

I have a smart plug connected to both display devices so that one is completely powered off when the other is working. I did this because I was having issues with Dolby Vision before when both display devices where connected to the AVR even if one was in standby. Because of this, I didn't think of physically disconnecting one device as a test - in my head, as one was completely without power, it should not have affected anything but lo and behold it did. Question now is why is it a problem now when it wasn't before???

I actually have a Vertex2 device connected between the AVR and the projector to make my projector "Dolby Vision capable" (a cheat I know). It appears as long as there is a second device connected to my AVR (whether is it the projector or only the Vertex without the projector), the AppleTV will only output a 1080p signal to the TV. I'll try and mess around with the Vertex settings to see if I can work around the problem. I still think there is something in the TV or AppleTV latest OS update that caused this issue to appear recently to begin with.
 

Jase

Distinguished Member
HDMI can do some odd things like that. I recall seeing something similar in one of the other AVR threads when both a PJ and TV are connected at the same time.

To be honest, I'm not entirely sure what the solution was. I think it might be having to manually select the HDMI Monitor Outputs rather than leaving it on Auto. I'm not 100% on that though!
 

techted

Active Member
HDMI can do some odd things like that. I recall seeing something similar in one of the other AVR threads when both a PJ and TV are connected at the same time.

To be honest, I'm not entirely sure what the solution was. I think it might be having to manually select the HDMI Monitor Outputs rather than leaving it on Auto. I'm not 100% on that though!
That would fix it I think but unfortunately on Arcams, both HDMI outs are always on at the same time. There is no manual switch or setting to select one or the other (which I think you can do on other AVRs). I asked this question of Arcam support in the past for a different but similar issue.
 

Jase

Distinguished Member
That would fix it I think but unfortunately on Arcams, both HDMI outs are always on at the same time. There is no manual switch or setting to select one or the other (which I think you can do on other AVRs). I asked this question of Arcam support in the past for a different but similar issue.
Ah, that scuppers that idea. Hopefully one of Vertex settings might be a solution to it as I'm not sure what else to suggest really.
 

techted

Active Member
Ah, that scuppers that idea. Hopefully one of Vertex settings might be a solution to it as I'm not sure what else to suggest really.
I recall now Arcam suggesting in the past to connect the 2nd display to Zone2 of the AVR. I can't remember why I didn't do that. Am sure if I try to do it again now, I'll suddenly remember why I didn't do it before!
 

techted

Active Member
Found that both my AppleTV AND PS5 refuse to output a 4K signal when BOTH display devices (TV LG OLED C9 & Projector JVC NX7) are connected to the Arcam 850 at the same time. There is an HDFury Vertex2 box in between the AVR and the JVC NX7 projector.

I have a smart plug on both displays and it used to be that having one display device disconnected from the power using the smart plug solved the problem but recently I now have to physically disconnect the hdmi cable connecting the AVR to the Vertex box for it to work like it used to.

I later found that moving the smart plug from the projector to the Vertex2 box instead fixes things.

Sigh ...
 

Joe Fernand

Distinguished Member
AVForums Sponsor
Good you got your system working. I’d normally connect the Sources to the Vertex2 then Output from the Vertex2 as separate video feeds to the TV and Projector plus HDMI Audio to the AVR, you would lose the Arcam OSD but likely not have to worry about using the power switch.

Joe
 

techted

Active Member
I would but I have more sources that the Vertex has inputs unfortunately.

And I spoke too soon. Have to go back to physically disconnecting an HDMI cable to one display device. Looks like that even with the Vertex powered off, the two display devices are interfering with one another. Thought it worked initially, putting the smart plug on the Vertex but later testing showed it wasn’t.
 

Joe Fernand

Distinguished Member
AVForums Sponsor
I’d power everything off and connect as per previous post with your four ‘key’ sources and see how it goes - assuming that works reliably you could add a low cost switch in front of the Vertex2.

Another option would be to try an HDFury DR HDMI 4K on one of the AVR Outputs and control what EDID the Arcam sees.

The way Arcam polls the dual outputs tends to cause problems.


Joe
 

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