Macbook Pro 16 M1 not waking up monitors

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

• on invoking Option-(Detect Display) button 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.

Hello MoElwekil,

We will need to do some more exploring to find out how to resolve this.

If your Mac sleeps or wakes unexpectedly start with the steps here.

If you can’t see your Mac desktop on an external display start with the article and quoted steps below:

• Close the lid on your Mac notebook computer to put it to sleep.• Connect the power adapter to your Mac and a power outlet.• Reconnect your Mac to an external display.• Connect a USB keyboard, mouse, or trackpad to your Mac.• If you’re using a wireless keyboard, mouse, or trackpad, make sure it’s turned on.• Wait a few seconds, then press any key on the external keyboard, or use the mouse or trackpad, to wake your Mac.• If your wireless keyboard, mouse, or trackpad isn’t connected (paired) with your Mac, Bluetooth Setup Assistant opens so you can connect them.

We hope this helps.

Cheers.

Mohamed,

Thanks for the clarification.

Let's continue with these steps:

If your display is blank or not detected

Try these steps if you don't see an image on your display.

Check how many displays you can connect

To find out how many external displays your Mac supports, check its technical specifications page or use the Support tab in About This Mac: 

Choose Apple menu  > About This Mac.

Click the Support tab, then click Specifications.

On the webpage that appears, the number of displays your Mac supports appears under Video Support or Graphics.

Check your cable or adapter

Disconnect the cable from your external display from your Mac, then reconnect it. If the cable from your external display doesn't connect to the ports on your Mac, you can use a Thunderbolt 3 or USB-C adapter.

If your external display isn't detected or appears blurry on your Mac

If changing the adapter or updating the macOS software doesn't resolve this, please reach out to Apple directly: Contact Apple Support

Take care.