Mac users have reported another macOS Monterey 12.3 issue which prevents their computers from recognizing external displays connected via USB-C. According to complains on Apple Support forum, some external displays are not detected by Macs running on the latest macOS Monterey 12.3 update.
Apple released macOS Monterey 12.3 update to public last week and since then multiple issues have surfaced like a drop in the speed of PCI-E GPU cards,, in both eGPU enclosures and Mac Pro, the update bricked Mac models with replaced logic boards including the (2021) 16-inch MacBook Pro with M1 Pro chip and a few users, the update affected the functionality of their game controllers: Xbox, PlayStation, and other third-party wireless controllers.
Users report that on macOS Monterey 12.3, their external display do not output signal
The new macOS Monterey 12.3 external display issue is experienced by owners of Mac Mini, M1 MacBook Air, and 16-inch Intel- MacBook Pro. @ wrote on Apple Support that:
After updating my Mac Mini today to 12.3, my monitor now no longer displays an image via USB-C, just keeps saying on no signal on the monitor.
I have tried HDMI and same issue. The odd occasion it will display a picture but once I shutdown or restart the mac mini it does not display a picture. The mac is booting up. I have had to resort to connecting it to my old TV with HDMI connection.
This is so frustrating
I have tried resetting the SMC which had not appeared to work, also tried downgrading the displayport version from 1.4 to 1.2 (on the odd occasion I did get a picture) but that has not worked either.
Has anyone else having this issue? The monitor I use is a BenQ SW270C. This is really doing my head in and was wondering if anyone else has got a fix to this.
Same issue with dual BenQ PD3220U on a MBP16 (2019) over Thunderbolt-3.
Other affected users have shared the same experience after updating to macOS Monterey 12.3. For unplugging and then re-plugging after a few minutes worked temporarily and the issue emerged again the next morning.