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
Hi everyone,
Updated to Catalina, and had the same problem.
Two monitors, one of them a Wacom Cintiq 24 just turned black.
In the Displaysettings i saw the Contiq, but the screen was black.
Tried all the things described, but nothing seemed to work - except reseting the SMC.
Did this - and Voila! All good again.
Monitor and Wacom up and running!
Thank you for the advice!!
We recently purchased a 2020 MPR and a Thunderbolt 3 OWC hub to replace our previous 2014 MBP and OWC Thunderbolt 2 hub. The new hub is connected to a 4K Acer display. With our previous system the monitor would go to sleep when the MPB was removed or when it when to sleep. Now with the new system with Catalina OS, the Acer does not wake up when the MBP starts and we have to turn the monitor on and off when we start the MBP, and that does not alway work. Often I have to go to the Preference page to make a connection. I have contacted OWC and they were no help, stating the Thunderbolt 3 system turns off when the MBP disconnects. Looking here, this maybe a Catalina issue. I am considering a dedicated connection between the MBP and the monitor. Anyone have any other ideas?
If I understood correctly, you mac "sees" the display, as in:
1) "it appears in System Preferences" and also
2) "you can move your cursor" to where the display ought to be, but you see nothing"
With everything connected, try turning the display off and back on. Just the display, leave the mac on.
This is just for the future people who updated to Big Sur OS like I did and ran into an issue where I was not able to connect to my external monitor and I have done everything ( Multiple time connect and disconnect my HDMI-TYPE C cable, Reset NVRAM&PRAM and thereby finally restoring my complete laptop and even downgrading back to Catalina OS. But Nothing Worked!
Therefore, I understood later that the problem was with the display drivers re-calibrated and wont support all the third party kind of display cables. So I returned my existing Display wire (PORTconnnect) with a different third party wire (Prolink)
AND IT FREAKING WORKED!!!!!! ps - It was very important for me to work with an external monitor and everything was fine before I updated to Big Sur.
your best luck would be to buy the Apple Adapter for no future issues.
It does not hurt to try resetting NVRAM and SMC.
Also: is the display recognized if you boot into Safe Mode?
I just upgraded to Catalina, and after that my external displays would not be recognised. But... I have found that after the screensaver has kicked in and been cleared, the monitors are found again.
Did you ever figure out what the problem was?
After months of this problem, the solution was not an Apple usb-c to usb-c cable (neither one worked), but rather the cheapest knock off I could find on Amazon. Insane.
I'm having the same exact issue, and I am using an Apple monitor.
I solved this problem. If you are using DisplayLink devices/connectors you need to update the software every time you update the OS.
External display not working after installing MacOs Catalina
