Hello,
after upgrading my MacBook to macOS Catalina I can't connect external displays. Minutes before installation it was all properly working. It seems like MacBook doesn't detect them at all.
Anyone has similar issue? Any hints?
The displays are not Apple (HP, Asus).
Maybe this might point you in the right direction.
I fixed my full time pink screen issue, here is the solution. I think it might apply to your issue as well. For those of you without working screens, I suggest finding a screen that does work temporarily, and installing Teamviewer, or some other free program to remotely log into your machine. After doing so, connect the nonworking screen, start the computer, and log in remotely, then follow the steps 1-5 below. you will have to switch back to the working screen for the steps 6-15
The reason it is having an issue, is after the update, the signal being sent is YCbCr instead of RGB like your monitors are expecting. Some people with panels like mine will get pink, others likely get no signal recognized. This script works by setting up a profile for your specific monitor, and having it be forced to be RGB, if you connect it to another model monitor with the same issue, this process will need to be repeated for that monitor as well.
Hope this helps everyone! if you have issues look in the comments on the script page, the author is active.
My machine is a Mac mini (2018) i7 64GB 1TB. My monitor is a 28 inch Hannspree HF289H monitor
You've come to the right place...but read the threads on all the pages here. There is nothing new under the sun with your problem. The best bet is to replace the cables to your monitor(s) and mouse (although you are the first person I can recall mentioning the mouse). It's a long and bumpy road...but we are all waiting for Apple to fix the problem once and for all.
I don't know if the cause and effect are there, but when I started this morning, the monitor was not working. My "Clean Your Mac" updated to Catalina and I ran it. Voila! After completion with no restart, my external monitor suddenly appeared. Since "Clean MY Mac" cleans the RAM, it might have been the problem. Thanks.
This USB to HDMI adapter is working fine with me so far:
https://www.amazon.ca/gp/product/B013G4CJM8/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
After the Catalina upgrade, I updated Screen Recording to fix the black screen issue.
System Preferences -> Security and Privacy ->Privacy
On the left column, select Screen Recording
Select DisplayLinkuserAgent
markebrandon wrote:
... nor respond to the many forum posts that requested help with this.
Apple is not here. Apple Support Communities is a User-to-User support forum. If other Users can not help you think of a fix, No further help is likely to be forthcoming using this medium. There are no mechanisms for escalating problems to Apple Support from here, and Apple Engineering and Marketing Movers and Shakers do NOT monitor these forums looking for trends and outstanding issues.
Senior Contributors have been instructed to refer Users with unsolved problems to the "Contact Support" link at the top of every forum page.
Thank you @AnBarRua!
YOUR TIP SOLVED my longtime problem, since installing Catalina, and my external screen not working!
Here's my setup and what I did: I use an Apple Macbook Pro 13" from 2016 with top specs together with a first gen Apple Cinema external display. Sharing this so it might help others.
Old setup (that only worked sporadically and very random);
MBP > Apple USB-C adapter > Apple Cinema display normal connection cables (the one with one power and one data cable).
New and WORKING setup;
MBP > Apple USB-C adapter > Apple Thunderbolt cable > Apple Cinema display thunderbolt port on the screens hub. Not using the screens normal display cable as in above setup.
Have not had a single glitch on my external screen since I did this!
BTW & FYI:
I've done the same "trail- & error-journey" as you with every tip on this and other discussion-threads on the net, including trying many different adapters. Nothing worked and it all started when I upgraded to Catalina, before that I never had a problem with my external Apple Cinema display.
Thanks again @AnBarRua for this simple and great solution to this very stubborn problem :)
It does not help matters by saying "me, too" at the end of a very long thread, without providing any details.
You don't say what mac you have, what display or how it is connected.
Any "displaylink" software? Is it up to date?
Welcome to the HDMI club SallyAsha...we're all waiting anxiously for Apple to come out with a fix for this. Its a problem with Catalina...
How is it connected? Maybe all you need is a different cable.
Check with the Dock Maker to see if a software update is required.
Older version of Microsoft office are 32-bit Apps, and 32-bit Apps do not run under Catalina.
I have iMac 27" 2017 that worked fine with an external monitor ViewSonic VA2759-SMH plugged in directly from HMDI to USB-C this morning before upgrade to MacOS Catalina. Now the monitor does not show up in displays in system preferences even after "detect displays". Thoughts or wait for patch?
I tried plugging and unpluging several times and shutting down Mac. Nothing worked. Then on another Mac I just left it plugged in and after 30 min it lit up. When I connect and disconnect the screen doesn’t turn on immediately. The other Mac can’t even detect single external screen.
i can’t find any logic in how this works. Sounds like patch is needed.
Has anyone been successful with safe mode reboot?
Just purchased a 2018 mini today. Upgraded to OS Catalina and my external display (24" 1080p TV via HDMI) stopped working after working perfectly with OS Mojave. I was able to HDMI out to my stereo receiver and use my TV (4K). After trying the fix about adjusting the energy saver I was able to use my 24" display again. Thanks!
What cable did you buy? I have these two from Amazon that have been working really well until the upgrade; but I'll definitely look into upgrading if the CleanMyMac solutions isn't a consistent fix: https://www.amazon.com/gp/product/B07KJHKHSF/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
This is the one I bought. No science behind it, just looked at reviews and someone used it for dual display macbook pro 2018!
Hope it works for you if you try it.
https://www.amazon.co.uk/gp/product/B07CL2RHX5/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1
Following up. I ordered a new Apple Thunderbolt2 -> USB-C (yay for $50 adapters) since people have said to try new cables.
2018 Macbook Air <-> Apple adapter <-> Apple Monitor (these cables aren't replaceable)
Does not detect the monitor until roughly 30m-2h later. It does eventually detect it and start working. This problem is repeatable on multiple monitors. I used it for without problems until upgrading to Catalina which is when this problem started. I'm happy to provide whatever debugging info any Apple developer would like.
External display not working after installing MacOs Catalina
