Sidebar Sidebar
Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

How to stop MacOS from grabbing input on LG OLED?

T

Talesin

macrumors newbie
Original poster
Feb 9, 2025
3
0
Greetings, all!

I'm going to assume that my question is related to MacOS itself, rather than the specific computer, but in case it's relevant - I'm looking at an integration issue between my M4 Pro Mac Mini running MacOS 15.3 and an LG OLED65GXP series TV. The issue at hand - this Mac system grabs the input of my LG TV on a regular basis when I would prefer that it not. The Sequoia-based M4 recently replaced an old Catalina-based 2012 Intel Mac Mini that didn't exhibit this behavior.

The Mac Mini is used as a music server, and thus typically operates in a headless configuration. I'll log into it via screen sharing when needed, but I have it connected to my LG as a backup. For example, on boot, I need to type in the account password via an actual keyboard before I can access the Mac via screen sharing. I can now do that blind as I now know that it's required, but it was helpful to have the TV connected as a screen for such occasional use. (Again, with Catalina on the 2012 Mini, I didn't have to do this - I could login directly via screen sharing. I assume this is due to the increasing security features of each new MacOS release, but if there is a way to bypass the physical login on Sequoia in favor of the shared-screen login, I'd love to know that trick too!)

The LG has (4) HDMI 2.1 inputs, with HDMI-2 supporting eARC, which is where I have my Apple TV 4K connected. 99% of the time I'm using the TV, this is my desired input. The problem is that the Mac Mini keeps grabbing the input away from the Apple TV. It does this - twice - on boot (unless I wait for a long time), and continues to do it randomly while trying to watch content on the Apple TV. The Mac is essentially idle when I'm watching Apple TV content, so I'm not sure what's causing the input-grabs. (I do usually have the shared desktop up, but not in focus.)

Things I've tried or that might also be relevant:
  • Via the "Edit" option in the "Settings" menu of the "Home Dashboard" on the LG, changed the HDMI input for the Mac Mini to the "PC" icon and the Apple TV to a "Streaming Box" icon. (I thought these were just icons and didn't have a practical implication, but I've seen enough recommendations to do this in online search results that I did it anyway.)
    • This did seem to reduce the frequency of the screen grabs, but it always seemed random to begin with, and I still always get the double-grab on boot at a minimum.
  • On the Mac Mini in the Settings->Displays->"When Connected to TV"->"Mirror Entire Screen"
  • LG "Sound Out" is set to Optical+Internal Speakers (so I can route it into my AV system when desired). This routes to a Thunderbolt audio interface to the Mac Mini, but disconnecting it has no impact on any other behavior.
  • Screen Sharing is always in "Standard" mode, as the high performance mode grabs the audio as well (which is a neat trick, actually), and that causes other problems.
  • I don't want to disable automatic input section on the LG TV (Settings->Connection->"Auto Device Detection"), since it seems to be an all-or-nothing affair, meaning that I can't disable it for the Mac Mini HDMI input only.
    • In the same LG menu, I also have SIMPLINK (HDMI-CEC) and "Auto Power Sync" turned off. Again, these are all-or-nothing. The HDMI-CEC is useful more almost all connected devices, whereas the power-synching is really only used with my rarely used Blu-Ray player.
Does anyone have experience with such a setup, such that they might know the secret to making MacOS Sequoia less "grabby" of its input to an LG OLED?

Many thanks for your suggestions!
 
Talesin said:
I don't want to disable automatic input section on the LG TV (Settings->Connection->"Auto Device Detection"),
Click to expand...
Why don’t you want to disable? Have you tried disabling? Really does sound like that will do what you want.
 
As I said, you can't disable per input - it's all-or-nothing. If I could disable just for the Mac input, I would. But I don't want to lose the ability to automatically detect signal on the other inputs.

And as mentioned, this is also a new behavior that I'd like to understand - whether from the change in OS or the change in Mac hardware.
 
Good link - thanks! Based on that, I started searching on "Mac HDMI CEC" and found several similar threads on various forums, several of which also pointed to MacOS 14.4 (on Apple Silicon, specifically) as the start of the behavior. This one suggested the use of a CEC blocker on the TV end of the HDMI cable from the Mac - a type of device that I didn't know existed. I just ordered one to see if that does the trick. In the mean time, I've turned off every notification I can and that has reduced the input-grabbing a bit more, though obviously it does nothing for the initial post-boot input grabbing. I'll report back on whether the blocker works, though I'd suggest to Apple that a CEC settings menu allowing control over which CEC functions were active would be a welcome addition to a future MacOS!

And to address my other (admittedly buried) question - it looks like the requirement to directly connect via keyboard and screen after reboot (rather than screen sharing, etc.) is due to the use of file vault, which apparently results in the login screen showing from a pre-boot state in which the network isn't yet active. With file vault enabled, it looks like full booting, with networking, doesn't occur until after login. But I need to do some more digging to see if screen sharing vs. Remote Management will impact this in any way. (If the network stack truly isn't started when the login screen first displays following a reboot, then no form of remote display mechanism will work, but I've only just found the file vault tip and may not have all of the details yet.)

Thanks for the feedback so far - sometimes it just comes down to knowing what search terms to use. Any other input appreciated, as I'm sure there are subtleties of which I'm still unaware!
 
You must log in or register to reply here.
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.
Top Bottom
Back