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appkov

macrumors newbie
Original poster
Nov 27, 2009
14
0
Hello, this is my first time on this forum so I hope this is the correct place to ask this question. I own two Mac Pro (Late 2013) "trashcans". With one, I had been using two Apple Cinema Displays, both 27" Model A1316.

Mac Pro (Late 2013)
Processor: 2.7 GHz 12-Core Intel Xeon E5
Memory: 64 GB 1866 MHz DDR3
Graphics: AMD FirePro D700 6 GB

Two days ago, all the Thunderbolt ports on my first Mac Pro stopped working. I had upgraded to Monterey a few weeks ago and everything was working fine but I thought it could be the cause. Imagine my surprise when I plugged each monitor into my other Mac Pro (running Catalina) and found that all those ports didn't work either. I then thought that maybe it was the monitors but I plugged them into my old MacBook Pro laptop (running Sierra) and both monitors worked fine. Now I am really confused.

I am now using an HDMI monitor through the HDMI port of my main Mac Pro and the computer seems to be functioning perfectly well.

Any help would be very greatly appreciated. as I don't know how to begin to try to solve this issue. Cheers!
 

SpotOnT

macrumors 6502a
Dec 7, 2016
874
1,771
That is very odd! There have been some firmware updates for the Mac Pro, but if that was the issue, it would have happened when you upgraded your Mac, not a few weeks later. The fact that it is happening on two separate Mac Pros at the exact same time, still has me leaning towards some firmware/software incompatibility issue with the Cinema Display though. It seems unlikely you would develop the same hardware failure on two separate Macs at the exact same time.

How is your Mac Pro connected to the Cinema Displays? Are they the ones with DVI or Mini DisplayPort?

Do you have any Thunderbolt or DisplayPort devices other than the Cinema Displays you can use to further check the Thunderbolt ports on Mac Pro? My guess is still that they are working, they just aren’t working with the Cinema Display.

If you haven't tried already, a general rule of thumb for something like this is to try resetting the NVRAM and SMC. I wouldn't think it would help, considering both your Mac Pros are suddenly exhibiting the same problem, but I suppose it is worth a try.

How to reset the NVRAM, PRAM, and SMC
 
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appkov

macrumors newbie
Original poster
Nov 27, 2009
14
0
That is very odd! There have been some firmware updates for the Mac Pro, but if that was the issue, it would have happened when you upgraded your Mac, not a few weeks later. The fact that it is happening on two separate Mac Pros at the exact same time, still has me leaning towards some firmware/software incompatibility issue with the Cinema Display though. It seems unlikely you would develop the same hardware failure on two separate Macs at the exact same time.

How is your Mac Pro connected to the Cinema Displays? Are they the ones with DVI or Mini DisplayPort?

Do you have any Thunderbolt or DisplayPort devices other than the Cinema Displays you can use to further check the Thunderbolt ports on Mac Pro? My guess is still that they are working, they just aren’t working with the Cinema Display.

If you haven't tried already, a general rule of thumb for something like this is to try resetting the NVRAM and SMC. I wouldn't think it would help, considering both your Mac Pros are suddenly exhibiting the same problem, but I suppose it is worth a try.

How to reset the NVRAM, PRAM, and SMC
Thank you SpotOnT for taking the time to help, I really appreciate your kindness.

My Apple Cinema Displays were connected from a Thunderbolt cable that is hard connected to the monitor. I has a male Thunderbolt jack and a MagSafe connector. I plug the Thunderbolt jacks of the two monitors directly into the Thunderbolt ports on my Mac Pro. I have attached photos. The two monitor set up was working fine until suddenly it didn't.

Unfortunately I don't have any other Thunderbolt or DisplayPort devices on hand, I'll see if I can borrow one.

I'll try the resets tomorrow morning and see what happens. I have fixed a lot of problems with all the Macs I've had over the years (I started with the Macintosh 512Ke), and this one is really stumping me.

cables 1.jpg cables 2.jpg
 

arw

macrumors 65816
Aug 31, 2010
1,099
859
If you have at least a Tunderbolt cable, you can connect two Mac Pros directly and start one in Target disk mode to see if that works.

Your post is very interesting as I observed some weird Displayport behavior in my MPs as well after the latest firmware updates. HDMI works as it should.
In my case the problems do coincide with the firmware updates but as @tsialex pointed out, there haven‘t been any changes in years regarding the GPU part. And I’m not sure your other machine would have received a new firmware via Catalina.
 
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SpotOnT

macrumors 6502a
Dec 7, 2016
874
1,771
It might be worth checking what system firmware version you have on your two Mac Pros (you can see that in System Report under About This Mac). I know Catalina has been getting firmware updates with the Security Update patches, but I am not sure they have parity with Monterey at this exact moment.

While you are there, does System Report display all three Thunderbolt buses? If you try connecting your Cinema Display, does it show up as being connected on a Thunderbolt Bus or in Graphics/Displays in System Report or does your Mac Pro/macOS just not recognize the device at all?
 
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appkov

macrumors newbie
Original poster
Nov 27, 2009
14
0
If you have at least a Tunderbolt cable, you can connect two Mac Pros directly and start one in Target disk mode to see if that works.

Your post is very interesting as I observed some weird Displayport behavior in my MPs as well after the latest firmware updates. HDMI works as it should.
In my case the problems do coincide with the firmware updates but as @tsialex pointed out, there haven‘t been any changes in years regarding the GPU part. And I’m not sure your other machine would have received a new firmware via Catalina.
Hello arw, thank you for adding to the conversation, I appreciate your time. Unfortunately, I have never had any thunderbolt drives etc. so the only cable I have is the one connected to each monitor. It seems like it has to be something like firmware because both monitors work with my old MacBook Pro laptop (running Sierra).
 

appkov

macrumors newbie
Original poster
Nov 27, 2009
14
0
It might be worth checking what system firmware version you have on your two Mac Pros (you can see that in System Report under About This Mac). I know Catalina has been getting firmware updates with the Security Update patches, but I am not sure they have parity with Monterey at this exact moment.

While you are there, does System Report display all three Thunderbolt buses? If you try connecting your Cinema Display, does it show up as being connected on a Thunderbolt Bus or in Graphics/Displays in System Report or does your Mac Pro/macOS just not recognize the device at all?
Ok, suddenly this morning they all work again. I didn't change anything. Maybe it was behind the scenes firmware thing, very confusing. I am going to just wait and see whether they STAY working.
 
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SpotOnT

macrumors 6502a
Dec 7, 2016
874
1,771
Well that is very confusing indeed!

Do keep us posted if they stay working or if the problem comes back. Hopefully it was just some temporary issue, although I can't really think of what.
 
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