New M1 MacBook Air doesn't connect to 4K monitor over display port

Hey! It is Syntech USB C to DisplayPort Cable(4K@60Hz), Thunderbolt 3 to DisplayPort Cable.

I’m unsure if I can post links here but google will find it easily.

I've read in the latest release notes that this issue has been addressed but I returned it so cannot confirm.

Hopefully someone who faced this issue previously will be able to update to the latest OS and to confirm whether it’s resolved.

My wife's new Dell U2720QM Ultrasharp 27" 4K IPS LED, USB-C Monitor works perfectly with her new Macbook Air M1. The monitor is beautiful - sharp, clear, bold colors. It is connected using the USB-C to USB-C cable that came with the monitor.

What brand cable did u use?

*Update* -> I've managed to get the external display working using USB-C -> HDMI 2.0 cable. I've got full resolution and 75hz also.

It looks like the reason for TB/USB-C -> DP cables not working properly, or at all, is that the ports on the macs do not support DP Alt Mode. I'm unsure if you can get a cable which would work but so far I don't see any on the Apple Store website. Only Mini DP or HDMI but absolutely no DP cable available.

Please, correct me if I'm wrong but that's so far what I found out.

I have the same issue with an M1 MacBook Pro. I used to connect fine, but suddenly it quit working when I rearranged my desk and no it connects to my Samsung 4K monitor for a few seconds and then the monitor goes black. I was using the new OWC Thunderbolt Hub. I then unplugged connected directly. Still no joy.

Seems like a lot of folks having the problem with M1 Macs - Air, Pro and mini.

The title of this thread has the words 'display port', this isn't a usb-c thread.

Have there been any updates, I cannot get dp or hdmi to work from a dock either.

MBP TB3 --> Dock --> (HDMI) | (DP) --> Monitor

With dp cable I get nothing, with HDMI I get colorful static.

MacBook Air / Espresso extension screen problem. I have a MacBook Air M1 and it won't connect to my Espresso extension screen. The older MacBook Air I used (2014) connected without trouble. Anyone else having this problem? Any work arounds? Rob

Ok thanks for the response!

I have a 4K display that works on USB-C to DisplayPort and mine does recognise it. However, it doesn't seem to be able to support display scaling. It isn't clear whether or not this is a limitation of the hardware or a bug.

Hey! I've got the same problem with my Asus XR42CK. It always worked via TB -> DP but with my new Macbook Air M1 it doesn't display anything. The system recognises the monitor with no issues (the popup display settings window shows up on the macbook's screen) but the monitor is staying pitch black. No matter what port I choose, I even bought a new cable with no luck.

HDMI -> Apple's adapter -> USB - C works (with a slight delay) but that's about it.

I really hope this is a software issue rather than the M1 not being capable of transferring data via DP.

I have the exact same monitor (Acer xr342ck) as Amicable and am experiencing the same issue with my M1 MacBook Air. I'm using a Mini Display Port -> USB-C cable to connect my monitor to my MacBook and while the MacBook recognizes the monitor in System Preferences, nothing actually shows up. I know for sure that this cable works because I use it to connect my work laptop (a 2017 13" MacBook Pro) to my Acer monitor and can get 3440x1440 resolution at 60hz.

Switching to a HDMI 2.0 -> USB-C cable works perfectly with the M1 MacBook Air and I even get 75hz. Unfortunately, I only get 30hz using the HDMI cable with my work MacBook pro.

*Small update

I discovered that if I shut down my MacBook Air, connect the Mini Display Port -> USB-C cable, then turn the laptop back on, it starts to output to monitor (albeit at the wrong resolution). It only outputs for a few seconds before the monitor stops displaying anything. This leads me to believe that this is some kind of software issue.