Looking Glass not detected on 2017 MacBook Pro


I got my Looking Glass today and tried hooking it up to my MacBook Pro with no luck - the LEDs came on, but the display was never detected. I disconnected all other accessories, rebooted, connected the USB cable before the HDMI, and then the HDMI before the USB all without success. This is a MacBook Pro with 4 USB-C ports and I tried with 2 different adapters.

Here are the specs:

MacBook Pro 15-inch, 2017
Processor: 3.1 GHz Intel Core i7
Memory: 16 GB 2133 MHz LPDDR3
Graphics: Radeon Pro 560 4096 MB

Adapter 1:
Apple USB-C Digital AV Multiport (https://www.apple.com/shop/product/MJ1K2AM/A/usb-c-digital-av-multiport-adapter?fnode=8b)

Adapter 2:
HyperDrive USB-C Hub (https://www.amazon.com/HyperDrive-Type-C-Adapter-50Gbps-MacBook/dp/B01MUAEI7J)

I’m not sure what to try next.


Hi Jay,

Did you see the MAC screen flicker ( the screen go black for half a second and then back on ) when HDMI cable plug in? If you don’t see the flicker, possibly the HDMI has poor connection. Could you please plug and unplug the HDMI cable to see if it can connect properly?


No, I don’t see a flicker.

Yes, I’ve tried unplugging and replugging and even tried a different HDMI cable (one that’s usually connected to a 4K monitor so I know that it’s working).


Hi Jay,

It looks that the USB-C to HDMI adapter may not support 2560X1600 @60Hz. Could you please test it on a Windows machine or MAC pro which has a native HDMI port?



I’ve connected the display to a PC and the Looking Glass is working - so it appears that it’s just not working with my Mac HDMI adapter.

I thought I saw in another support thread that this is the adapter that used in-house at Looking Glass Factory, but I might be misremembering. Is there a Mac HDMI adapter which has been tested/approved for use with Looking Glass?


Hi Jay,

Now that you’ve confirmed that HDMI works with another machine, I’m reasonably confident that this is an adapter problem rather than a defect with your Looking Glass, so we’ll work to get you sorted.

Regarding hubs: we typically use these, but I do believe we’ve also had success with the Apple multiport adapter. For what it’s worth, these USB-C devices don’t have the bandwidth to deliver both a USB 3.0 hub and a 60Hz display out at greater than 1080p, so in order to get the maximum refresh rate you either need to step up to a Thunderbolt adapter (expensive) or buy a cable that goes directly from USB-C to HDMI (no hub / internal electronics).

Most of our Mac work in-house uses machines with native HDMI so it’s good to get some feedback on this issue. I bought a popular USB-C / HDMI cable and will test it tomorrow to ascertain whether we can recommend it as a reliable option for people experiencing this issue.

For what it’s worth, I would expect one of the multiport hubs to reliably drive a Looking Glass at 30 Hz. Mac GPUs will probably bottleneck multiview rendering before screen refresh rate becomes perceptible, so this may not be an issue for you at this time.

I’ll do a little bit more research into the sorts of USB hubs that tend to work with the current generation of Macs and get back to you with more suggestions shortly.

Thanks for your patience!



Thanks for the info - I’ve ordered one of the adapters you linked to and it’ll be here Friday. I’ll retest after it arrives.

In the meantime, the Looking Glass is hooked up to our gaming PC and the kids’ minds are blown so mission accomplished!


Hey @jaygrieves! Nikki here from Looking Glass Factory. I just experienced this on my own Macbook Pro with a Looking Glass unit here in the lab and I thought we were running into the same issue. After a bit of troubleshooting, I realized that I had my displays extended and that my extended screen (running in the Looking Glass) was set with a black background and so I had assumed nothing was flashing in my Looking Glass when in fact it was a problem with the display orientation itself.

I doubt that it’s the same problem you’re running into to but I wanted to just mention it anyway. I wanted to make sure that you were running in Mirrored and not Extended when connecting the Looking Glass to your Macbook!


Hi Jay -

We did just confirm another Looking Glass that works with a PC but not with a Mac, where the same Mac subsequently worked perfectly with a different Looking Glass. Are you still experiencing this issue? If so, we should continue this conversation via email.

Sorry for the slow responses - hope your vacation went well. I did end up testing that cable out and it seemed to work fine, so I’m curious to hear if you had any success.



When my LG first arrived I tried it on my MacBook Pro 2017 using a SATECHI multi-port adapter that has HDMI. It does not work (was just green). Then I tried the Apple adapter and it worked. However, the machine does not have enough horsepower for the demo software, so I switch to a beefy PC with an NVIDIA GPU. Good luck!