I got a new MacBook Pro from late 2016, MacOS Sierra, 2 thunderbolt 3 ports.

In this machine I need to plug in one external monitor via HDMI, and a few USB devices (mouse and keyboards). For this I bought an adapter that plugs in to the Mac's USB-C port, and supplies two USB 3.1 ports, one HDMI port and a power delivery for the USB-C power supply. The adapter is: Promate uniHub-C (https://www.promate.net/products/unihub-c)

The power supply works, when I plug in the power cable to the adapter, the computer charges.

The HDMI works with another monitor.

My external USB hard drive works, so the mouse/keyboard issue feels strange.

When I have a USB keyboard plugged in, and an external hard drive - the System Report > USB shows as follows. The keyboard and the hard drive are both plugged in to the uniHub-C.

In the finder I see the hard drive though, seems to work well.

Screenshot showing the System report System report

Screenshot showing that the finder can find the connected hard drive My Passport is found

Here is the problem: the USB slots doesn't seem to do much. When I plug in mouse and keyboard in the adapter, nothing happens. I was worried that perhaps I need another kind of USB-C => USB 3 adapter for regular USB devices to work, but I can't confirm that.

How can I verify I have an active connection in each USB slot?

  • What does System Report show under USB when using the adapter? - In generel, no further adapter should be necessary for connecting a USB mouse/keyboard.
    – jksoegaard
    Jul 20, 2017 at 13:29
  • I added this info in the edit now, I'm not sure if this is expected output.
    – miphe
    Jul 20, 2017 at 14:03
  • How is the hard drive connected? - Via the uniHub-C? The output you have from System Report does not show the hard drive, so it seems you haven't copied the output correctly?
    – jksoegaard
    Jul 20, 2017 at 15:40
  • The uniHub is connected to the laptop's thunderbolt-3 socket, the hard drive and the keyboard are connected to the uniHub. The uniHub is also connected to the wall socket for power, and to a monitor via HDMI. I updated the question with some screenshots.
    – miphe
    Jul 21, 2017 at 7:07
  • Is your external HDD a USB3, or USB2 device? Jul 31, 2017 at 8:19

2 Answers 2


It looks like this particular product (uniHub-C) has its own idea about compliance to USB specifications. The designers seem to cut off the USB 2.0 part of the VIA hub design. First sign is that their marketing blurb doesn't mention support for legacy (HS, FS, LS) devices, which is strange - in marketing, more is merrier. Second, the web page shows some goofy "USB Super-fast" logo, which in no way corresponds to the official USB-IF certification logo,

enter image description here

I suspect you fall for a wrong device.

  • This is concerning indeed. My hard drive is probably USB3, it's a MyPassport. So you think that USB2 protocols doesn't work with the uniHub but since the hard drive is USB3, that's the reason that one shows up?
    – miphe
    Aug 1, 2017 at 8:58
  • @miphe, why don't you try any known good USB 2.0 pen drive in your hub? I am sure you have several on them in your drawer... Aug 1, 2017 at 16:12
  • 1
    I have confirmed that this is the case. I purchased a USB-C => USB 2.0 HUB/Adapter (tinyurl.com/y79emk4j) and the components that didn't work with the Promate HUB does indeed work with this one. Thank you.
    – miphe
    Aug 4, 2017 at 11:07

I have the same problem with this hub:


Peripheral connection doesn't work (power, display and network do), and seems to be known issue (search for peripheral or Logitech) in the comments.

I connected another USB C hub in the other port in my Macbook and it indeed works.

Dongle hell.

Edit: from the comments in the link above and elsewhere I have read, some of these USB C Hubs have a problem with input devices connected at the same time (power + something else) from the same Thunderbolt port in the Macbook.

I have reached out to the manufacturer to see where the fault might lie, and if there is a mitigation. For now, using another hub without power/display in the other Thunderbolt port works.

  • Welcome to Ask Different. Would you perhaps edit this to explain how it addresses the main idea - how to tell if a port and device work. We generally remove "me too" answers, but this question wasn't super clear so I don't want to remove your answer until it's clear or documented what the known issue is.
    – bmike
    Jan 27, 2019 at 22:59

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