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Dell monitor connected to Mac Studio won't wake up from Sleep.

I have a Mac M1 Studio and a Dell U2715H monitor. When waking from sleep the monitor won't wake. Once even got the no input error.


[Re-Titled By Moderator]

Mac Studio (2022)

Posted on Apr 29, 2024 6:21 AM

Reply
12 replies

Jun 10, 2024 3:21 PM in response to krzyz

That six foot adapter/cable is too long for reliable operation at high resolutions. it needs to be one meter (three feet) or shorter.

What resolution on each display?


Your HDMI port can support a display up to 4K at 60 Hz directly, provided a high-spec cable is used. Perhaps you could saw the two displays.


If you post the make&model, Readers can look up the specs out each display and advise whether they could be swapped..

May 3, 2024 8:08 AM in response to WheelieNick

the monitor is connected directly to the Mac studio with a USB-C to display port (full size) cable

from the system report:

DELL U2715H:

  Resolution: 2560 x 1440 (QHD/WQHD - Wide Quad High Definition)

  UI Looks like: 2560 x 1440 @ 60.00Hz

  Main Display: Yes

  Mirror: Off

  Online: Yes

  Rotation: Supported

May 3, 2024 8:22 AM in response to krzyz

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.


Modern Displays with multiple ports are sometimes busy scanning the other ports, looking for an input, and miss the query from the Mac. They need to pay attention to the port you are actually using, or they will miss the query.


Some displays have On-Screen Display settings that can be used to tell the display a computer is attached on a certain port, or a certain port should be highest priority. Changing those may make your display more responsive.


Some displays include their own private "sleep" settings for the display alone. This can allow the display to enter its own sleep mode, on top of the Mac's not sending it data. A display that is sleeping on its own cannot respond to the Mac's query, and will stay dark.


Dell monitor connected to Mac Studio won't wake up from Sleep.

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