Resolved in 26.3: MacBook Pro HDMI fails EDID enumeration post-Monterey; display detected, but Vendor/Product IDs missing, output black

[haralds]

I spent hours trying to overcome a bug on MacBooks since Sonoma. I validated, it works on my M1 that supports Monterey.
The screen is not displaying. It is being detected but it is only showing black. The entire screen or display is affected. This is happening on multiple MacBook Pros running Tahoa, and Sequoia and Sonoma.
Internal displays are fine. This is happening with specific monitors. Displays shows the monitor vendor and model.
Research shows this has been a known bug since Ventura, when the software display architecture was changed. This is pretty egregious!.
EDIDs are the data block provided by monitors. Some of them are ignored on MacBooks. The same moinitor works fine on Mac Mini, and as I mentioned, when you run Monterey.

 

[haralds]

My workaround is a Cable Matters 48Gbps Unidirectional USB-C to HDMI 2.1 Adapter for macOS.
I used DisplayMenu to force the correct resolutions (3840x1620, 3840x1620), and with some delay, the handshake succeeded.
But Geeze, Apple. This worked, and you broke it for FOUR generations of macOS on all MacBooks .

 

[BillyJoeJimBob]

Perhaps OpenCore Legacy Patcher will become more popular as abandonware becomes more ubiquitous. 🔧

 

[haralds]

OCLP does not work on Apple Silicon, and these models are fully supported. The M4 is pretty new.

 

[kasakka]

Which monitor makes/models?

 

[BillyJoeJimBob]

OCLP does not work on Apple Silicon, and these models are fully supported. The M4 is pretty new.

Now there's a problem worthy of throwing AI at it: OCLP for Apple Silicon.

 

[haralds]

I had filed a Feedback, and was just contacted by an engineer to test with the latest version. This was fixed in macOS 26.3

My Samsung Odyssey G75F now works perfectly over HDMI! All supported resolutions show up.