Torn Lid angle sensor

@flannelist - this seems odd… The hall sensor angle data won’t effect the sleep/wake from the other sensors. This sensor only makes sense if the display is at an angle. As the set is a simple digital one it doesn’t really need calibration.

The only issue of calibration in this series is if you install a virgin display. I’ve replaced a few displays without needing to deal with calibration, using used displays so why is this sensor different?

Remember the Apple repair docs are thinking new not used.

@danj So. Because I never had to think about this, and now you sent me down an I have to find out everything about why this is the way it is rabbit hole, here’s what I found.

It’s not actually a hall effect sensor in the way that most laptops have an “OH there’s a magnet here, send the I’m closed signal!” sort of way. It actually has the ability to track more precise lid angle.

But to the calibration point. Couple things to mention.

1. Because Apple. The more they can serialize, I think the more satisfied they are with their ability to monopolize the repair space on their own products.

2. Running System Configuration on these model requires actually closing the lid during the configuration process. It’s probable the sensor needs to know what is open and what is closed since the magnet actually turns with the hinge.

3. This sensor also provides data to the board component which controls secure mic disable. Which also gets info from Secure Enclave. So there may be some cryptography at play here too.

@flannelist - But you missed the point when we replace a full lid assembly the calibration is held within the display logic not the logic board.

The sensor is not a magnetometer as it can’t detect the fields rotation. I had thought of that and I even put my scope to it to see what it’s transition was. The magnet field from the limited testing I did appears to be directional so the Hall sensor is setup as a simple no-go-no state. I didn’t have time to check the angle but I’m certain it’s about 45 degrees.

So while it would be ideal to calibrate, the simple fact is unless that feature was important replacing the sensor won’t effect the rest of the systems use.

@danj I'm updating my original response with a bunch of extra data I got from some additional digging. I'm not trying to be contrarian, I just want to make sure people have the full picture.

Sometimes repair is guesswork and sometimes its experimentation. I would just rather folks have the info to make an educated guess if they need to guess at all. Most people just want to fix their thing, and are not as invested ans I am, or you are in figuring out the mechanics of what and why.

I genuinely want to know how the mechanism here functions since it is different from the old fashioned logic present in most MacBooks or laptops. It is not a simple on/off hall sensor which rely on yes/no magnetic presence. Those hall sensors have 3 pins in most cases. The IC on the lid angle sensor has 14. That's a lot of extra data for yes/no.

@flannelist - Don’t get lost in the chips pin count. The sensor is not a single hall sensor as that wouldn’t work. Here we have at least three: Target and the Sides. A simple comparator is used to isolate the target angle from the left and right hence the simple no-go-no state.

I don’t have access to a system and spare part to tryout. I think you’ll find the system will work. Yes, Apple is going crazy with locking down it’s major parts. This is not likely to be Serialized. But the proof is with the pudding!