Monterey 12.3.1 External Monitor/Display Issue - No Longer Outputting Signal

Apple, this issue has persisted since macOS 12.0 was released. What was that? November? I'm getting really, really tired of this nuisance. Please use some of that cash you have from charging 5X as much as Newegg for RAM and hire some people to fix this already.

I had this same problem and could not find answers online. I am running Monterey 12.3.1 on a MacBook Pro16 with an LG 34WN80C monitor connected to the Mac with USB-C cable. I went to the monitor controls and after I verified that is was set to use the USB-C port, it suddenly connected. The Mac was connected by cable when I did this. No changes were made in any settings, I was just verifying the monitor setting. Really weird and doesn't make sense, but I'm now able to use the monitor.

I hope this helps someone else out there!

Is it an Apple USB-C/lightning cable you're using? Is it still working after a restart? I've had my second monitor suddenly receive an image too after changing the refresh rate but after a restart it went back to the "No Signal" message and changing the refresh rate didn't do anything.

Thank you so much for posting this! I just called Apple and the rep tried to "problem solve" with me but I explained that we had lost so many hours with IT already trying to solve this and that there are pages and pages on this website that so very clearly show that no tech has been able to fix it yet. So.... he reluctantly skipped those problem solving steps and is just sending me the adaptor! I had already spent $30 on an HDMI cord that someone else had suggested (worked for a day but then the cord - where it meets the monitor - would get so hot, that we would have to unplug it and let it cool and then replug it in for it to work - scary). So, YAY! And thanks so much for the suggestion!!

I have a 5K 120/240hz display so HDMI is not an option.

Belkin Thunderbolt 3 Dock Core, specified to be Mac compatible. No issues when running windows on bootcamp...

Wondering if this is a Bug or a Feature 🤦

Hi Apple

I have been using 2 LG UltraFine Monitors connected together at my 2018 MacBook Pro but suddenly 2nd monitor receives no signals although both monitors are working fine when I use just 1 monitor. I strongly believe this is Monterey 12.3.1 issue not any other hardwares. I just went to Apple store at Apple Park but employee over there had no solution. Please help for better work environment.

Augustin

I received the adapter and there is no improvement on my monitor. It continues to fade dark where I cannot really see anything then get bright and fade and sometimes black out completely. MacBook Pro 2019 with Lepow portable monitor. Worked perfectly for 2 years until 12.3 update. Still works perfectly on my old laptop running Catalina.

hi there, just wondering if you had any success? I also have a mac air M1 and am upgraded to monterey 12.3.1

I have a mac CINEMA HD external monitor that it has always connected to. At present in displays the only option when it comes to adding a display is the apple TV devices over wifi. It doesn't recognise anything plugged in and I have added the correct USBc adapter. it doesn't let me try to "detect display " at all.

Also frustrated!!!

Monterey: Same **** problems and start to be a serious problem. It compromise our business. It was perfect with BigSure.

device affected: MacBook Air 2019 + M1 with Dell UltraSharp U2722DE 4 k (Docking station on board)

device affected: MacBook Air with BenQ PD2710-T (Docking station on board)

no problem with the Dell P2722HE (that it's not a 4k) used with the same MacBook Air 2019

That's weird, it worked instantly for me and the image was still there after multiple restarts. Did you get the same adapter I linked? Did you try other USB-C ports too? Did you also try a different HDMI cable, maybe yours is causing additional problems with the new MacBook?

Btw, I tested my regular non-Apple adapter with my old Mac Mini (that's still got Big Sur) again yesterday and it was still working fine with my regular two-monitor setup, so it's definitely Monterey and/or something in the new Mac Mini causing the problem.

Yeah, they sent me the exact same one. Cord works fine with my older laptop running Catalina. Several of the techs I have spoken with have not even heard of this problem. The final I received last night was that we need to just wait for the next update.

Thanks. Yes Purchased the correct USB C male to dvi adapter. Works instantly when plugged in to husbands MacBook Pro also on Monterey 12.3.1 with all identical software but not on Mac Air M1 2020 .

I’m not sure if it’s an accessibility issue? Or if the thunderport (4 not 3 type) is different as it is on the pro as there is a slight difference when we checked via the serial number on the Mac tech specs site

Update. Called support again as the adapter they kindly sent did not solve the issue. Today after a good 45 minutes of troubleshooting the tech asked if I had factory reset the monitor after the update 3.1. I had not so we gave that a try. SO FAR SO GOOD! I will work the day and see how it goes but so far it has been working normally. I am using a Lepow Z1 portable monitor connected via usb-c to usb-c with MacBook Pro 2019. If you have not factory reset you might give it a go.

Same. Absolutely maddening.

2021 MacBook M1 + LG 32UP83A-W. Worked great on 12.3. Updating from 12.3 → 12.3.1 broke it. None of the approaches I've seen bring it back. Just crazy. How does this widespread of an issue survive testing? Bonkers.

And to Bormo - This doesn't have anything to do with "Apple being more interested on correct gender speech and diversity" than bug fixes. This isn't zero sum. That's just you polluting a totally unrelated space with your own issues.

Yes, please everyone contact support. The techs I have spoken with have not yet taken any of these calls. Also, one more thing to try, my monitor finally started working today after I did a factory reset on the monitor. So far, with half a day of work it has steadily worked properly.