Monterey Beta 8 - problems with external display

After updating to Beta 8, I can't seem to get my external display to work. The backlight on the monitor turns on and it seems to interpret some data from the MacBook briefly displaying a flash of colors and then going black with the backlight still on. The Display is still fully function on a different Mac.

Macbook Pro 2016, display connected to external thunderbolt 3 hub.

Answered by IgnacioAF in 689793022

As a workaround, I installed Beta 6 (complete pkg) over beta 8 to restore my display use. I guess the solution will be in the next beta (9).

I had the same issue with the public release of Monterey on my MBP with a USB-C connected LG 4k monitor.

What fixed it for me was unplugging all the devices from the ports on the monitor, and reconnecting the monitor after rebooting without it connected.

I am having the same issue with Release Version on my 2019 MBP 16". First external USB-C connected 4K monitor works fine but as soon after plugging in the second USB-C 4K monitor trackpad stops accepting clicks and then a minute or two later the trackpad stops working and then about 5 minutes later system crashes and reboots.

These monitors are the same DELL 2415Q and it I switch monitors and plug the other one first it works fine but when I plug in the other the exact same behaviour so this is not a monitor issue.

Was this not fixed before the release???

Thanks

Thanks

Same here MBP M1 with a USB-C and a Benq GW27 just upgraded to Monterey (12.0.1).

If I just try to connect and disconnect a couple of times in the end it works.

Restart the MacBook. Close the lid when the loading bar appears. The loading will continue on the external monitor and then you can proceed to open the lid and the external monitor will still stay connected.

Hey guys! Have the same issue where my external monitor glitched out or some crazy stuff has happened with it after Monterey was installed on my MacBook Pro 16 (2019). First annoying thing was that I couldn't log in to the laptop when an external display is connected - after type in the password, it's jumped into crazy colors and offered to type in the password again and again and again. The second annoying thing is that Davinci Resolve crashed every time I opened it on an external display or used display as a video clean feed. Mental.

The solution that worked for me was changing the color profile of the external display. I changed it to TV Monitor because my laptop works just fine with my TV. This pushed me to the thought that it's a weird situation going on and I tried a different color profile.

Hope it can be helpful somehow.

I got the same issue on my macbook pro 13' 2018 and a ThinkVision 4K display. It's fixed by changing the TypeC-HDMI line to a TypeC-TypeC line. Just have a try and hope it works for you guys.

I have the exact same issue after updating to the release version yesterday. This is not a beta anymore and I still can't use external displays on My 13" M1 Macbook Pro.

I experienced a similar issue when I installed 12.0.1 today on my MBP 16 that's about 18 months old. The refresh rate in the display settings on the computer defaulted to 30 MHz. I changed them to 60 MHz and it fixed the issue.

I have 2x LG 27UL650 displays. My system would freeze on shutdown, restart, sleep, lock, etc. I entered recovery mode and reinstalled the OS. Same result. Updated the LG drivers. Same result. I reset NVRAM. Same result. My system booted, restarted, and slept fine without the monitors connected. Then I read about the issue here. I reconnected one monitor, set the refresh rate, and the system restarted normally. I repeated the process with the second monitor.

I had this exact problem, and this is what solved it for me. This is what fixed my issue on Big Sur as well.

  1. Clear up the desktop - move ALL desktop items away from the edges and corners of the screen.
  2. Hide all application windows and close all Finder windows.
  3. Reconnect the external monitor.

This brings my external monitor back online. I can only surmise that it was caused by some sort of resolution or refresh rate mismatch between my MBP monitor and the external one. Any time anything could potentially be overlapping both displays, this happens when waking up. I hope this works for you too. I'm on Monterey now, and this has brought my external back, but the resolution is still messed up, so that's my next thing to tackle. Good luck!

finally got my external display to work on MacOS 12.

I just change the refresh rate on my external monitor:

System preference > Displays > Display Settings... > "external monitor" > Refresh Rate

I toyed around with different refresh rate till the monitor starts working.

Let me know if it helps!

I installed Monterey 12.0.1 couple of days ago. External monitor (thunderbolt - displayport) stopped working during update. It's not even regonized. HDMI-HDMI works though. I'm using Early 2015 macbook pro. I tried everything. Resetting SMC, NVRAM & PRAM, re-installing monterey, installed catalina, linux and windows. It just isn't working anywhere.

I had the same issue after upgrading my MBP 2019 (Intel) to Monterey. My external Samsung C34J79x monitor was no longer charging the laptop via the TB3 connection and was also not being recognised in clamshell mode (laptop would just turn off as it thought it was being sent to sleep).

The fix was to change the display settings of the external monitor to 60Hz.

However, this is not ideal as I prefer the refresh rate and feel of the 100Hz. A fix for this issue would be highly appreciated Apple, it's a shame to have gone backwards in this new OS and to also not be able to use my monitor to its fullest capabilities!

I upgraded to Monterey 12.0.1. Release notes https://developer.apple.com/documentation/macos-release-notes/macos-12_0_1-release-notes say: 'There might be issues with wakeup when dual monitors are connected. (79839446). Workaround: Connect the power adapter that came with the Mac.'.

On Big Sur, my external monitors never worked without the laptop being connected to external power.

At work, I have two HDMI screens from Samsung connected to the USB-C port on my macBook through a Satechi hub. Both monitors are configured as Extended displays. The displays work unless I close the lid of the laptop. Then all go black.

At home, I have only one Samsung HDMI screen, configured to mirror the laptop. Here, I can work with closed lid. This monitor is also connected to a Satechi hub, but a different one as the one at work.

My AOC monitor, which was just purchased, also went out of order. I shouldn't have upgraded MacOS Monterey 12.0.1. I hope Apple will solve this problem soon.

After upgrading to macOS Monterey on my Macbook Pro, my external monitor no longer works and no longer shows up in displays. The screen flickers, turns black and repeats this pattern. Very difficult to work without two screens. On phone with Apple for about two hours and was told Apple has no resolution. I am sorry I upgraded. I only did so because my Macbook Pro not syncing with messages on iphone. Apple told me I needed to upgrade after being on phone with them an additional two hours for this problem which is not resolved. Now I have two issues. Very frustrating.

Monterey Beta 8 - problems with external display
 
 
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