Unable to wake my computer using the keyboard in clamshell mode after update to Sonoma

OK, So while on the phone to Apple Support, I recognised that the battery icon was NOT showing that the system was running on mains power, but the battery instead.

Mains power being the operating power source is signified by the power plug looking icon being over the top of the battery icon.... not the lightning icon which signifies charging as it does on all devices...

Clamshell mode will not operate unless there is a mains power source if lid is closed.

This is why the extended display works on battery power, but drops off when you close the lid. Giving the impression that clamshell is the issue.

By unplugging my multi hub (bon.elk ELK-80029-R . An approved hub as it is sold at Apple in Australia) and reconnecting it to power, the mains power icon was present and the clamshell mode therefore enabled....

I'm no expert, but i believe there may be a compatibility issue between Sonoma and some multi hubs. Mains power not flowing through as it did on Ventura for some reason.

I'll monitor this and see if reseting the multi hub (disconnect and reconnect power) fixes the clamshell issue next time it occurs.

If so, i might try a new multi hub and see if that resolves the issue.

If others can please confirm the above and suggest a multi hub which has worked well for them that would be great??

I tried Kadzzy's solution, no dice, I'm using a Dell 2K external monitor on hdmi. Nothing has changed in my setup, including the adapters, and clamshell mode was dead since the upgrade to Sonoma. I read in another post however (I don't remember where, reddit I think) about getting the OS to "Detect Displays" - with the new preferences panel, you now need to do the following:

1) connect external display.

2) open Displays preference panel.

3) press the 'option' key.

4) the "Night Shift" button now becomes the "Detect Displays" button, you press this.

5) Make sure the Macbook is charging/waiting to chargae (lightning bolt on the battery icon or powerplug icon on the battery icon).

6) close the laptop lid.

For some unknowable reason, this worked for me. Either it was remembering a display configuration incorrectly, or there's been an update to the hdmi version that's confused things.

A co-worker had a similar problem, but he was using a charger that wasn't providing enough power, and the macbook would sleep when in clamshell mode. It was intermittent because this was happening only when he had an external hdd connected, and it was just enough to throw him over the threshold. He switched to a 90w power supply from 60w, and he was okay.

Good Luck

Currently on software version 14.1.1 on the 2020 MacBook Pro. I am using the display link software to connect a HDMI cable from my ultra wide display to the usb-c port on my MacBook.

The solution that worked for me can be implemented as follows...

1. Going to the battery section of the settings and toggling the option "Prevent automatic sleeping on power adapter when the display is off" to off.
2. Additionally for my display link software specifically I had to go to the settings and toggle "Power save all displays and sleep in clamshell" to off

note: I could only get this to work while the MacBook was connected to power. (original power cable and power brick used)

Under these conditions I was able to get clamshell to work on my MacBook. Hopefully this helped somebody.

I noticed that multiple people were mentioning that apple might be navigating away from enabling clamshell, but what seems more likely is that they are moving away from clamshell as a default implementation. This was likely implemented for better longterm battery maintenance, as people who don't use the feature can accidentally leave their Mac in clamshell mode (using unnecessary energy and battery cycles).

I have a new macbook pro and I have two thunderbolt connected thru usb c and the clamshell was not working after I upgraded to sonoma 14.0. I just updated to 14.1 and the clamshell started to work again.

Thank you very much for your answer!! You solved my problem. I did not have the power connected to my laptop so whenever I closed my laptop, the monitor screen would go blank and I was unable to wake it up. Now that the power is plugged into the laptop, the monitor mirrors perfectly from the laptop.

I got some new monitors and encountered the same issue. I seem to have solved it by making one of my external monitors the "main" one - which is done by moving the dock to it (by navigating to the monitor with your mouse and then keep moving "down" at the bottom, and the dock will show up).

After doing that, I closed my MacBook and the monitors did not go to sleep - clamshell mode is working great now.

I can confirm the same thing. After reading this, I unplugged the multi hub, flipped the plug around for good measure, and plugged back in. After that I heard the connected to power source tone and saw the icon for it too. The clamshell problem was immediately solved.

I was having this exact issue after the Sonoma update on my 2020 MacBook Air. After fiddling with settings and cables, I realized all I needed to do was keep the screen on...while the lid was closed. I use Ascrono docks for my MBP and Air. The MBP was not having any issue after the update, only the Air. So, I tested how far the Air would open after it was in the dock, connected to power. There is definitely some wiggle room. I slid something thin in between the screen and the keyboard after it was docked in clamshell. Not exactly sure if it is touching the keyboard but I think it is touching a key. I noticed that this opened the Air just enough that I could tell the screen was on. There does not seem to be too much pressure on the dock or Air since the object is really thin. Once I did that, I heard the familiar crackle of my monitor coming to life. Everything works now. Not a perfect solution but, maybe something for now.

Same issue for me - 14" 2023 MBP M2 connected to 1 ext display via hdmi, running 14.4.1. It was working, but I disconnected everything to work in a different room, upon returning it would no longer support clamshell mode.

My solution was to change to the other hdmi input on my monitor, this seems to have resolved my issues.

In my case the external display is connected to the MacBook via HDMI. When the lid is closed the MB goes to sleep (black screen external monitor) and wake up is not possible with the external keyboard. The lid needs to be opened to get to the login screen. This is different from Ventura where the MB, external display and external keyboard would remain “on” when closing the lid.

I was having an issue with my 2019 16" MacBook Pro and my 4K LG monitor where the screen was staying blank when in clamshell mode after upgrading to MacOS Sonoma, but I found a solution on Reddit from two years ago that solved it! Maybe it'll help someone else too. (I was also having an issue where the external display wasn't working at all, even when not in clamshell mode, but that's another story.)

Here's the solution that worked for me, edited a bit to apply to Sonoma and what worked in my specific situation:

1. Open your MacBook lid so you're in dual screen mode.
2. Open the "Displays" tab in System Settings.
3. Choose your external monitor to view its settings. Then click "Advanced" and toggle on "Show resolutions as list."
4. Hover your mouse over the resolution that says "(Default)" next to it. For me it was 1920 x 1080.
5. Close your MacBook lid, and go into clamshell mode. Don't move your mouse/trackpad--the cursor needs to stay in the same place.
6. Give your MacBook a few seconds to make sure it's in clamshell mode.
7. Then click your mouse/trackpad.

As long as the display settings window stayed in the same place, and as long as you didn't move your mouse around, you will have been able to select the default option for clamshell mode even though you couldn't see anything on your external monitor. After doing that, the screen should come to life!

The first time I tried this, clicking my mouse on the blank screen in the place where the default resolution was supposed to be didn't seem to work, so I opened my MacBook back up and noticed the Settings window was gone, so I closed and opened Settings back up and tried again, clicking a bit sooner too, and then it worked! It made everything larger at first, since the default resolution/size for this 4K monitor was 1080p, but after choosing that and my screen coming back to life, I was able to switch back to the 1440p size setting, and everything works now as it should! :)

The separate article that Used to describe how to use your Mac in closed-clamshell mode has been removed. Apple has been hinting for some time that they have no love for that feature.

Readers here are not likely to have any magic bullets for you . It is entirely possible it is no longer supported.

ask Apple support:.

Official Apple Support

Apple support (3rd line) was not able to help. After some experimenting it seems to be related the HDMI communication between MB and external display. When connecting the display via an HDMI to USB-C adapter, clamshell mode works but with purple screen colouring. So no solution, but proving the HDMI direct interface is buggy.

Meanwhile I'm using Sonoma V14.1.1. Still the LG Ultragear+ display is not working in clamshell mode when connected via HDMI directly. When using a HDMI dongle and connecting to the MacBook USB-C port, clamshell mode works but the colours are tinted towards purple. So that didn't seem to be the solution.

But...

Then I changed to the second HDMI port on the display and back to direct HDMI on the MB (so without USB-C dongle). All of a sudden clamshell works as intended. Even after switching back to the first HDMI port, clamshell mode remains operational.

In summary, the order that miraculously worked in my case:

1. MB-HDMI to display HDMI1 (starting situation)
2. MB-USBC via dongle to display HDMI1, lid closed --> clamshell works but purple screen
3. as 2 but now display HDMI2 --> clamshell still purple screen
4. MB-HDMI to display HDMI2 --> clamshell works as intended (no more purple screen)
5. as 4 but back to display HDMI1 --> clamshell remains working

(side note: sometimes in clamshell mode the external display randomly blanks for a second... this also happened with Ventura)

<<. I am using the display link software to connect a HDMI cable from my ultra wide display to the usb-c port on my MacBook. >>

DisplayLink comes in TWO parts, and BOTH are required to actually implement DisplayLink.

• You need the DisplayLink software.

• You need a non-trivial DisplayLink 'stunt box' with DisplayLink chips inside that provide display output signals with proper timing and a screen buffer.

The connection between the two is 'USB or whatever is available' NOT a display protocol, so the 'stunt box' is required to hold a screen buffer and provide the display output signals.

So if you have connected a USB-C port with an adapter to HDMI cable, you are NOT using DisplayLink to run that display -- that is a "real" display.