Apple Put a Hinge Sensor in the 16″ MacBook Pro. What Could It Be For?

Apple Put a Hinge Sensor in the 16″ MacBook Pro. What Could It Be For?

Since their inception, MacBooks have used standard on/off magnetic sensors to go to sleep when you close the lid. But then we heard from MacRumors that there might be something different about the latest MacBook Pro. Sure enough, there’s a magnet sensor in the new 16” model, but not where you’d expect it.

The magnet added to the hinge of the 16" 2019 MacBook Pro

The newest MacBook has a magnet embedded in the hinge, with an etched arrow indicating its alignment and polarity. As you raise and lower the display, the arrow and magnet rotate in kind. Near that magnet-capped hinge, inside the bottom case, is a new sensor on a flex cable. The sensor can detect the hinge magnet’s angle, and presumably also keep count of how many times the display has been opened and closed.

The hinge sensor in the bottom half of the 16" 2019 MacBook Pro

It’s not hard to guess what a directional hinge magnet and sensor are for, but further proof is found in an internal notice provided to Apple Authorized Service Providers, obtained by MacRumors. Apple mentions a “lid angle sensor” in that document, and indicates that, after a display repair, technicians must re-calibrate the lid angle sensor (using Apple Services Toolkit) for the repair to be complete.

Close-up of the hinge magnet and sensor in the 16" 2019 MacBook Pro

Lest you think we simply forgot to look for this sensor in previous MacBooks, you can see the absence of a hinge magnet or sensor in a screen replacement guide for the previous 2019 MacBook Pro. And while there are still magnets to keep the lid snugly shut on the 16” model, we didn’t spot the typical Hall effect sensors that most laptops, including those made by Apple, use to detect those magnets and determine when the display is closed enough for the display to turn off.

But this hinge sensor doesn’t seem to be doing anything obvious, at least yet. From our observations, the 16” MacBook Pro goes to sleep at about the same angle as previous MacBooks, and most other laptops—maybe marginally higher, but only just so. 

Those are the facts; now let’s speculate! What could Apple be up to, adding more specificity to their hinge sensor? Our teardown team had some thoughts. They are listed here, in no particular order—except that we can’t help but think about Flexgate first when we think about MacBook Pro hinges.

  • As stated in our teardown addition: “It could be a clever way for Apple to trace the history of how the device was used if repairs are needed. For instance, if the display cables fray, Apple might want to know how much the display was adjusted, and how often.”
  • Given the impressively thumping/self-canceling speakers inside this MacBook, could the speakers adjust their volume, tone, or mute themselves, when the lid is closed? (But why would Apple not brag about this?)
  • Maybe future displays will adjust their saturation, contrast, or make some other unforeseen change based on the angle of the display.
  • A better reading on a partially shut lid could add another layer of security to the MacBook’s hardware mic disconnect feature.
  • Perhaps it allows macOS to automatically adjust a FaceTime camera (whenever they actually update it) based on the angle of the screen.
  • Or maybe it’s some kind of salve to office workers who shuttle from meeting to meeting with their laptop open just enough to keep it from sleeping (a.k.a. “The Placeholder”)

What other kinds of uses could Apple have for knowing the precise angle of a laptop display? Let your guesses run wild in the comments.