Thunderbolt Display's additional hardware works with Bootcamp partition but not macOS

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Thunderbolt Display's additional hardware works with Bootcamp partition but not macOS

I recently acquired a 27" Thunderbolt Display to use with my 16" 2019 MacBook Pro via a Thunderbolt 3 to 2 adapter. However, it has a problem in that macOS (Sequoia 14.7) only recognizes the display panel, and none of the hardware that connects via the PCIe lanes. The camera, speakers, and additional ports do not show up in System Information and are unusable. Curiously, Windows 10 (22H2) on my Bootcamp partition has no issues with the display at all: it recognizes all of the additional hardware in the display, and even automatically switches audio output to the display's speakers upon connection.

Some reading indicates that this is a symptom of the built-in octopus cable failing, and while I have ordered a standalone Thunderbolt 2 cable to test this, the fact that Windows has no problems with the display leaves me a little confounded. Other reading suggests that older macOS versions are more tolerant of faults on the PCIe lanes than newer version, but it seems like this must also apply to Windows. Anyone else experience something like this?

MacBook Pro (2017 – 2020)

Posted on Sep 20, 2025 12:56 PM

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Answer 1

Top-ranking reply

Grant Bennet-Alder

Level 10

138,833 points

Sep 21, 2025 12:58 PM in response to LucasVN

<< Only device shown on the Thunderbolt device tree is the display panel; nothing else. >>

That is as expected, because those other devices are USB devices, so they should show in the USB pane.

¿Do they?

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Answer 2

Sep 20, 2025 5:12 PM in response to LucasVN

start by checking Option-Apple menu, top item, system information.

Look on the USB section and thunderbolt,section for any trace of the camera.

if not found, give your display a timeout:

disconnect it from all power and all data and leave it alone for a quarter hour or more.

Pointing into the corner, or sitting on the naughty stair are optional.

Presuming that hardware is seen, you may need to re-check security & privacy settings to be certain it is allowed to be accessed by the apps you use. For example, the camera: Typically, Photo Booth does not need any special access, so it is used as the test case.

Also check the amount of current required and supplied for each device.

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Answer 3

LucasVN Author

Level 1

20 points

Sep 21, 2025 12:33 PM in response to Grant Bennet-Alder

Grant Bennet-Alder wrote:

Pointing into the corner, or sitting on the naughty stair are optional.

LMAFO! xD

But anyhow, plugged back in after a full day, and no change. Only device shown on the Thunderbolt device tree is the display panel; nothing else. Same behavior occurs on the only other Thunderbolt-equipped system I have (13" Late 2011 MBP). By contrast, Windows 10, and now that I've upgraded to it, Windows 11 on my Bootcamp partition, work perfectly. The speakers, camera, and USB, Firewire, and Ethernet controllers all show up in the Windows Device Manager, and aside from the Firewire port which I can't test due to not owning any such devices, all of them work perfectly aside from the speakers being duplicated in the Windows sound settings. I do have a regular Thunderbolt 2 cable arriving tomorrow, so I'll try connecting the display with that to see if that makes a difference.

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Answer 4

LucasVN Author

Level 1

20 points

Sep 21, 2025 1:45 PM in response to Grant Bennet-Alder

They do not show up at all. To macOS, the speakers, camera, and USB, Firewire, and Ethernet controllers simply don't exist. The EFI boot picker, for that matter, also doesn't recognize them: my Logitech G Keyboard and mouse don't work there when connected through the display, but do work when connected via an Anker USB hub.

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