Garbled display on Looking Glass with 2018 MBP


Just received my Looking Glass and have issues getting it to work properly. Currently seeing this when playing the test scene:


  • MacBook Pro (13-inch, 2018, Four Thunderbolt 3 Ports)
  • 2,7 GHz Intel Core i7
  • 16 GB 2133 MHz LPDDR3
  • Intel Iris Plus Graphics 655 1536 MB
  • OSX High Sierra 10.13.6


  • For USB I’m using an USB-C - USB-C cable instead of the USB-C - USB-A cable provided.
  • For HDMI I’m connecting via an El Gato dock’s DisplayPort, with a HDMI-DisplayPort converter. So it’s MBP <-> USB-C <-> El Gato dock <-> DisplayPort/HDMI converter <-> Looking Glass.

I’ve tried various USB ports on the MBP, various USB-C cables (including the packaged cable with an USB-A/USB-C converter) and various restarts.

I’m still getting this garbled image seen above.

An additional note, the background light switch + the 4 buttons in the front (are these interactive buttons? Not sure, might be a dumb assumption it wasn’t 100% clear to me) also don’t seem to have any effect when pushed.

Please help, what else should I try? Thanks!

[RESOLVED] Garbled, Sliced, and Warped: "No calibration data from Looking Glass"

Hi there! Just from this picture alone (thanks for sending that btw) it seems that the calibration data isn’t reading to your computer at all seeing that there is no serial number seen on the test scene (that’s what 00000 means!)

We’ve actually tested out a specific set of cables that works to transmit you unique calibration data from your serial flash drive to your Looking Glass so I am guessing that because you’re not using the USB-C / USB-A cable that shipped with it, it’s not sending the data properly!

If you’re able to dongle up (ugh i know!) and use the cable we shipped with, that should solve the problem :slight_smile:

UPDATE: (oof - I read on, seems that you did try that. Did you do a hard restart on the computer with this cable plugged in - with the dongle - and see if that works?)

Also flagging @kyle @alxdncn to see if y’all have any other ideas of why this might be?


Thanks for the quick reply. So far I’ve tried an USB-C/USB-A converter that I got for a Pixel 2 which did not seem to work. Yes I also tried hard reset with these cables plugged in. Putting an image of it here as well for future reference:

I’ll try an official Apple dongle as well.

Could you provide more detail on what’s the property that these cables / converters need to have in order to have that calibration data flow through? Don’t have much hands-on experience working with USB on such low levels but would be interested in the details here. Is this about some optional parts of the USB standard?


Update: I’ve also tried out an Apple USB-C Digital AV Multiport Adapter, connecting both the HDMI and packaged USB cables to it, with the same results (tried cold restart as well) :frowning:



Let me start by saying that we’ll definitely get you up and running – if the following doesn’t work, please let me know at and one of us in the team will hop on a call with you to get your Looking Glass fully operational or get you a replacement if it turns out something is amiss in your particular system.

Like @nikki mentioned, the problems you’re seeing with the garbled image and the buttons not working (yup, they are interactive in most of the apps that run on the LKG) are likely related to the cable not making a stable connection between the Looking Glass and your computer.

We have a near duplicate of your Macbook Pro rig at our lab and have had good results with the official Macbook Multiport Adapter: So, I’m confident this will work if we sort out the adapter issue, and if there isn’t a problem with the Looking Glass hardware you received.

If you can, please give that a try with that Multiport Adapter. That said, if you’ve already ordered the other official dongle you mentioned, that also has a good chance of working. We’ve had a lot of poor results with unofficial adapters but good results with the official adapters.

And please make sure to use the included angled USB-C cable in this test – that has been carefully matched to engage reliably (I hesitate to use this word in this debug thread!) on the Looking Glass side and we’ve seen intermittent results with other cables.

Let me know how it goes!



Gah! I just saw your post that you tried the exact adapter we are using in the lab.

Please email me at and I’ll get you a replacement unit to see if it’s on the Looking Glass side.



Thanks, I’ll drop you message then and check back here once we came to some resolution!