Multiple External Displays

I am running the beta on a Macbook Pro 15" Mid 2015 model. I have 2 external displays plugged in to the MBPs two thunderbolt ports.


However on 10.12.1 suddenly only one display works at a time. If I have two plugged in, the first one plugged in will work. The second one will act as though it were not plugged in. If I unplug the first, then the second one will activate.


I switched backed to my partition without the beta and this is not an issue. I have filed a bug with Apple but I wanted to see if anyone else has seen this or similar external display issues.

Accepted Reply

Yay, Beta 4 solved the problem !

Replies

I'm having the same issue.

I'm having similar issues. I have a MB Pro 15" mid-2015 retina in a Henge dock. Attached are two 27" Thunderbolt displays and a 32" 4k mointor over HDMI. In macOS Sierra 10.12.0, rearranging the monitors in the Displays preference would cause the preference pan to crash multiple times. I finally stabilized it. With 10.12.1 beta, my Retina monitor is not on but the external monitors are. The display preference pan shows all four monitors as active.

It sounds like your issue was resolved with macOS 10.12.1, that's interesting. I had no problems whatsoever before that beta was installed. In fact if I switch back to my production partition using the 10.12 GM the problem goes away for me.

Identical issue. Also checked in 10.12.1 Recovery to ensure the external displays would function there and they do, in fact, work as expected. Pls let us know how your bug submission gets along.

I'll keep you posted on any response I get from 

Not an ideal solution, but I had the same issue with two external displays connected over DisplayPort. I fiddled around with a couple of different configurations and found that if I had one display connected over TB and the other display connected with a VGA cable and attached VGA to DisplayPort dongle (Apple OEM), they all work. I have no idea why that would work since they're both ultimately connected via DP. Obviously won't help anyone with two Apple TB Displays, but might help someone.

I installed public beta 2 (16B2333a) this morning, still seeing the problem. I submitted a report on the previous beta, guess I'll submit one on this beta.

I have the same issue as Paul's. The only difference with my externals is that I have one connected to a TB and the other via HDMI.

I have a 2012 Mac Mini with a Apple Cinema 27" LED(at the end of Thunderbolt chain from OWC ThunderBay 4) , and an HDMI Display connected. As of 10.12.1(16B2333a) Beta, randomly when display wake up from sleep, the Apple 27" Cinerama display goes dark(after about a half second of being on). The only way To bring it back to life is to reboot the computer. This same configuration has been working flawlessly until now. Except, since switching to Sierra, when displays wake up, they stay on for 1 second, then they go dark for a couple seconds, and then come back alive. Before(before macOS Sierra GM), they woke up without any glitches. And now Apple Cinema 27" goes dark after waking up(randomly).

I have the same config and the same problem :-(


Apple Diagnostic tool displayed this code VFD002

Having the exact same problem. OS won't even acknowledge the other display. I have one plugged in via display port to DVI and the other directly via HDMI. When I unplug one, the other works, but I can't get both to work at the same time. Even Beta 3 (10.12.1 Beta (16B2338c)) that was released today doesn't fix the problem. Kind of frustrating.

They just updated the status of the bug I filed as a duplicate. This is usually a good sign.

I downloaded beta 3 today. Unfortunately it didn't fix it. So I just downgraded to Siearra released version on that Mac Mini. Funny thing is, I am typing this on a 2012 MacBook Pro Retina with macOS 10.12.1 Beta 3(16B2338c), and it has two external displays on it(1 Cinema 27 LED, and one Cinema 27 Thunderbolt) and they both work fine. This problem seems to involve an HDMI in conjunction with a DisplayPort, which is what I have on that Mac Mini.(or Thunderbolt, this is a conjecture).

Same problem here since Beta 3. One connected over TB and the other over HDMI.

Same for me. Mid 2015 rMBP. Two displays connected HDMI > Thunderbolt, only one works at a time.