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m_x_uk Author

Level 1

9 points

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

Top-ranking reply

techieman75

Level 1

15 points

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.

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

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