Unable to get video from an M1 MacBook Air or Intel iMac via USB-C

My Spectrum is working correctly on my Windows PC via HDMI and everything looks great. When I plug my M1 MacBook Air to the USB-C input, switch the input on the Spectrum, the Mac charges, but doesn’t detect a second display. The Spectrum eventually says “No Signal” and goes to sleep. I’ve tried the same on my Intel iMac with the same result. I’ve tried the USB-C cable that came with the Mac as well as a USB-C Thunderbolt cable from my 24" LG that I know works.

I’ve updated the Spectrum to the latest firmware, and it didn’t help. Has anyone else seen this?

1 Like

Look’s like someone has a similar mac issue here 4K 144Hz over USB-C from MacBook Pro? - #12 by farvz

I am also having the same doubt. I don’t now if the type C cable can be directly used for display purposes. In my case is not working either…

There’s 2 things that can be easy to overlook that could be the cause of display connection problems with a USB-C cable.

(1) The cable has to be plugged into the USB-C port at the bottom of the Spectrum, right next to where the power cable plugs in. The USB-C port on the side, just under the regular USB ports, is only used for connecting peripherals to the USB hub

(2) The cable needs to be a proper USB 3.x cable, with a transfer speed of 10Gbps or more for DP1.2 or 40Gbps for DP1.4.

There are a lot of USB-C cables on the market that are mainly intended for charging, and they’ve only got the USB 2.0 wires connected.


Thank you for the response!

  1. I’m definitely plugging into the downward facing USB-C port.

  2. I’ve tried the Thunderbolt 3 cable which came with my LG UltraFine 4K. On that monitor, I’m able to get 4K60 with this cable.

I’ll play around with it a little more today.

So then it is confirmed that we cannot display the MacBook in the spectrum using the C type cable that brings the Mac?

Ok, used the USB-C cable that came with my external hard drive and it works.

@Luque535 I think we can confirm that the charging cable that comes with MacBooks won’t work for using the Spectrum as an external display.


Yes, data-transfer speed of the Apple USB-C Charge Cable is limited to 480Mbps and it doesn’t support video. But I don’t know why your tb3 cable didn’t work :thinking:

Anyway, congratulations!