Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

MacBook Pro is not sending the signal to the Dell monitor via Thunderbolt 3

Hi guys! Probably, I am not the first one asking this question, but anyway... I can not connect my MacBook Pro (13-inch, 2020, Four Thunderbolt 3 ports) to the newly bought Dell P2721Q. I get the following message: "Scanning for signal" then "No USB Type-C signal from your device". I tried resetting NVRAM and SMC, even reinstalled macOS on that machine, but no luck. The funniest thing that it works on my second MacBook Pro (13-inch, 2017, Two Thunderbolt 3 ports) with both Thunderbolt ports. And on both machines, there is the latest version of macOS Big Sur which is 11.0.1. Maybe you already heard about a similar issue and already know the answer? Thanks in advance.

Posted on Dec 12, 2020 1:27 PM

Reply
Question marked as Best reply

Posted on Dec 12, 2020 4:52 PM

I had a similar issue. Make sure you are using the ports on the left side of the Mac. I was unable to get things to work using the right side ports. Also make sure you disable auto switching on the dell monitor. Also make sure you have a high quality thunderbolt cable as all cables are NOT made the same. It needs to be a thunderbolt compatible cable not just a standard usb-c cable. Hope this helps resolve your issue.

Similar questions

1 reply
Question marked as Best reply

Dec 12, 2020 4:52 PM in response to m_x_uk

I had a similar issue. Make sure you are using the ports on the left side of the Mac. I was unable to get things to work using the right side ports. Also make sure you disable auto switching on the dell monitor. Also make sure you have a high quality thunderbolt cable as all cables are NOT made the same. It needs to be a thunderbolt compatible cable not just a standard usb-c cable. Hope this helps resolve your issue.

MacBook Pro is not sending the signal to the Dell monitor via Thunderbolt 3

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple ID.