Mac Studio won't output display signal over USB-C or HDMI

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Mac Studio won't output display signal over USB-C or HDMI

Hi, I just received a Mac Studio M1 Ultra today. Right out of the box, it would not display anything to my Lenovo T32p-20 4K monitor via USB-C/thunderbolt. The monitor works fine with the same cable on my MacBook Pro M1. Same issue if I connect via HDMI - no output. The only way I can get a picture is my unplugging and reconnecting USB-C to the same port. However, after reboot, the problem comes back again.

Both my computers are running 13.2.1. I will try a different monitor and will report back.

Mac Studio (2022)

Posted on Mar 25, 2023 2:19 PM

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Answer 1

Mar 25, 2023 2:52 PM in response to ksattic

The Mac uses a system that reminds me of “Plug and play” to determine what display is connected, and what its capabilities are.

To get a Mac display to become active, you need the Mac to query the display, and the display to answer with its name and capabilities. Otherwise, the display will not be shown as present, and no data will be sent to the display. "No signal detected" is generated by the DISPLAY, not by the Mac.

This query is only sent at certain times:

• at startup

• at wake from sleep — so momentarily sleeping and waking your Mac may work

• at insertion of the Mac-end of the display-cable, provided everything on that cable is ready-to-go

• hold the Option key while you click on the (Detect Display) button that will appear in Displays preferences (from another display)

so try doing some of those things and see if the display comes alive.

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