"Open Clamshell” - MBP Clamshell Mode without Restricting Airflow?

[XNorth]

Here’s a trick to use clamshell mode and save power without sacrificing air flow through or across the keyboard. I call this open clamshell mode.

The lid/main display will turn off without closing all the way. Slowly close the display to about an inch of the palm rest, about the width of a thumb. I use my thumb as a stop to quickly block the lid from closing. the display will turn off, and the extrnal display switches on as the main display. The gap allows better airflows than completely closed. This also works on a vertical stand with the lid open facing up.

Honestly, I don’t know if there is any difference in temps between clamshell mode and open clamshell mode, but I have been using my MBP 16" in open clamshell mode only when I’m not mobile. If anyone is willing to compare the temps and show open clamshell has lower temps, then this would be a legit way to have your cake and eat it too.

 

[profcutter]

You can also just very carefully place a small magnet on the hall effect sensor on the top case. That will fool the computer into thinking it's closed, and you can have the display all the way open. On my old 2013 MBP, it was just about an inch from the hinge on the left speaker.

 

[XNorth]

That doesn't seem to work with the 2019 MBP 16". And wouldn't a magnet put the Mac to sleep?

 

[profcutter]

The Hall effect sensor may be at a different spot on the 16. Maybe take a paper clip and run it around the edge of the screen, not touching but very close. If it pulls in a certain place, that’s probably where the sensor is. Just a thought. I found mine on some schematic I found a few years ago.
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The magnet puts the computer to sleep, but if you give it any input while the magnet is present, the internal screen remains off and the computer wakes up.

 

[robvas]

can anyone verify the air comes through the keyboard?

 

[XNorth]

Air is not channeled through the keyboard, but external airflow over the keyboard likely helps with heat dissipation when the keyboard and the Touch Bar get hot.

 

[XNorth]

The magnet puts the computer to sleep, but if you give it any input while the magnet is present, the internal screen remains off and the computer wakes up.

I can confirm that magnets don't work on my MBP 16". Maybe I'm not doing it right. The upper corners of the lid and edges of the palm rests are magnetized, but attaching a magnet to any of these spots have no effect.

Regardless, I prefer the open clamshell mode. I like the space saving low profile tucked under the monitor, in addition to the other benefits.

 

[profcutter]

The trick is to put the magnet on the topcase in the area corresponding to where the magnets are on the lid. The lid holds the magnets, the topcase houses the sensors. The sensors detect when the magnets come near.

One summer, when I was writing a book, I had the laptop raised up so there was some airflow underneath, it was connected to a 4K monitor, with the magnet on the topcase and the lid open, I could run the monitor at 60hz, and the fans ran like crazy. I never bothered to check if it ran cooler that way, but you could feel the hot air escaping above the keyboard, I figured that wasn’t good for the display to absorb when it was closed.

 

[Noxwiz]

What if you were to mirror your display and turn the MacBook brightness down to zero ?

 

[gold333]

What if you were to mirror your display and turn the MacBook brightness down to zero ?

You lose performance, because it is running two displays at once, even though one has the brightness down to 0.

Anyone know of a program to enable clamshell mode with the lid open ?

Closing the lid and running, causes the screen to display non removable burn in areas of different color, because of the heat.

EDIT: Found it: works perfectly and is free

GitHub - epalzeolithe/DisableMonitor-3.0

Contribute to epalzeolithe/DisableMonitor-3.0 development by creating an account on GitHub.

github.com

 

[AgentPotato]

For those saying a magnet works for lid close on the 2019 MBP 16"- I think it uses the lid angle sensor in the hinge, so the old magnet trick doesn't work...

 

[AgentPotato]

This works in Ventura?

You lose performance, because it is running two displays at once, even though one has the brightness down to 0.

Anyone know of a program to enable clamshell mode with the lid open ?

Closing the lid and running, causes the screen to display non removable burn in areas of different color, because of the heat.

EDIT: Found it: works perfectly and is free

GitHub - epalzeolithe/DisableMonitor-3.0

Contribute to epalzeolithe/DisableMonitor-3.0 development by creating an account on GitHub.

github.com

 

[thedrub]

The trick is to put the magnet on the topcase in the area corresponding to where the magnets are on the lid. The lid holds the magnets, the topcase houses the sensors. The sensors detect when the magnets come near.

One summer, when I was writing a book, I had the laptop raised up so there was some airflow underneath, it was connected to a 4K monitor, with the magnet on the topcase and the lid open, I could run the monitor at 60hz, and the fans ran like crazy. I never bothered to check if it ran cooler that way, but you could feel the hot air escaping above the keyboard, I figured that wasn’t good for the display to absorb when it was closed.

Hello @profcutter

15" 2017, i7, 16GB

I tried magnets. No luck. On this model the magnets are in the body, not the display (lid).

Why did I try?

1. Broken display
2. External monitor, which runs just fine in "clamshell" mode
3. I want to install Linux so want to boot from a USB drive. Want to use it "headless", over a network.
4. I cannot simultaneously (1) leave the display closed and (2) hold the power button to get into recovery mode.

Had hopes of fooling the lid closing feature. Tried steel pieces on the case. No luck. Tried small rare earth magnets on the case. No luck. Tried them on both the screen and the case. No luck

Any solutions out there????? Thanks