Edit (11/2/19): This post was updated to clarify and add information on more of Apple’s repair apps.
No mere mortal, lacking Apple’s stamp of approval, can completely fix the company’s products. You can do a lot, but in the newest iPhones, you can’t restore Touch ID, install a new battery, or replace a screen without a warning. Trying to replace core Mac parts can trigger a lock-out. No sacrifices or incantations can overcome this.
Instead, Apple’s official repair procedure requires proprietary software tools, available only to Authorized Service Providers and members of Apple’s unlaunched Independent Repair Program. We’ve previously written about Apple’s internal diagnostic software, which Right to Repair legislation aims to make available to the rest of us.
What, exactly, can Apple-approved folks do with all this secret software-that-shall-not-be-named? Let’s dive into what we know. And take a look at Samsung’s own secret repair app, while we’re at it.
Apple’s Cloud-Based Diagnostic & Calibration Tools
First off, Apple’s diagnostic software has a name: Apple Services Toolkit 2, often abbreviated as AST 2. Once you know that, you can find it mentioned and even pictured in many places: on Apple’s own discussion forums, on PDFs inadvertently posted publicly by university IT help desks (ahem), or even in the dark corners of YouTube.
You can only access AST 2 with an active connection to the web, and an authorized account with Apple’s private Global Services Exchange, or GSX. With an account, and certifications installed on your MacBook or iPad, you can then service Apple devices. You need a device’s serial number, which can be either read off the device in front of you or given to you over the phone. This remote connectivity is how Apple Store employees can check devices on the store floor, without lugging around cables or computers.
Next, you enter the category of problem you’re trying to fix: “Fan,” “Charging,” or the like. The device gets a request to allow a diagnostic tool to run. Presumably, there is a workaround for devices with entirely broken screens, likely involving a USB cable, but we haven’t seen it in action. After the access request is approved, a diagnostic tool checks everything: battery, Bluetooth, cameras, sensors, Touch ID, the works. Pretty neat!
AST 2 can show you what’s wrong with a device, along with a lot of details you can only see if an Apple Store employee is feeling cavalier and generous. One thing to note is that AST 2 provides a cycle count for an iOS device battery. Cycle count is important information that every device owner should have! Unfortunately, Apple has banned apps from their App Store that show cycle counts for mobile devices, creating a cottage industry for apps like Coconut Battery.
AST 2 is (perhaps obviously) not the first diagnostic app that Apple has made—AST 2’s precursor was a totally different tool, and it’s still used to fix older devices, mostly from 2013 and earlier. You can see AST 1 (technically 1.5) in action in this Italian video of a MacBook Air repair.
If something needs fixing or replacing, Apple’s equivalent of iFixit guides are available through the GSX site (check the left-hand column in this screencast). Apple’s Authorized Service Provider Manual notes that GSX grants you access to “take-apart, upgrade and repair procedures, basic servicing information, troubleshooting flow charts, product specs, adjustment procedures, and exploded view diagrams with part numbers.” That all certainly sounds like useful information!
AST 2 isn’t just helpful, it’s mandatory. Apple technicians cannot order parts for an Apple device until they’ve run a full diagnostic on the device at least once, even if they already know what needs fixing. And newer Macs with T2 security chips will not function until a full diagnostic has been run on them after the repair.
After a hardware repair, newer Macs with T2 chips require that a separate program, Mac Configuration Utility (MCU), be run while connected to another Mac via USB or Thunderbolt cable. This re-enables parts like logic boards, top cases, Touch ID, displays, and flash storage. Without doing so, a Mac’s screen will read “Waiting for session,” and will not function until the MCU is paired and executed. A similar tool, RepairCal, is needed to re-enable batteries, Touch ID, and screens on newer iOS devices.
Apple has sworn everyone with access to secrecy (with the exception of a few helpful/careless public posts). According to Apple’s Authorized Service Provider Manual, a basic requirement of being an authorized Apple tech is that “Apple’s repair and screening process must be kept confidential and can not be disclosed or visible to any third party, including customers in the service location.” That secrecy is helping no one. It prevents competent repair professionals from doing work they would be perfectly capable of, and leaves Apple’s customers in the dark about their own hardware.
Samsung’s “Must” Toolkit
We know even less about Samsung’s diagnostic software, but it has similar functionality. Samsung’s software is mentioned on Geek Squad, mobile repair subreddits, and on XDA-Developer threads. The XDA forums reveal the app’s actual name, Samsung Galaxy Must, along with a (dated) screenshot.
We were able to see this software for ourselves with a behind-the-scenes tour by an authorized Samsung service provider. It is also quite full-featured: Samsung’s software can verify battery health, touchscreen calibration, whether the phone’s firmware or software has been unlocked or modified (i.e. “rooted”), and read an internal barometer to determine the state of its water resistance. According to the iFixit staffer who got the tour, that screenshot is out-of-date, but it gives you a sense of what tools are available.
Like Apple and Samsung, most manufacturers keep their calibration and diagnostic software secret, hiding useful features from their customers. In testimony opposing Right to Repair laws, these companies argue that releasing this software will undermine their security model. Apple notably told lawmakers in Nebraska that releasing this information would turn the state into a “mecca for hackers.” Testifying in Boston on Monday, expert repairer Louis Rossman shredded similar arguments made by tech industry trade groups.
But not everyone is so user-hostile: Dell and HP happily make their diagnostic software and service manuals available to the public.
Secret Repair Tools Are Ridiculous and Wrong
Access to tools that tell you what is wrong with a device, explain how to fix it, and retain functionality after a repair is precisely the kind of thing the world needs if we’re going to push back the tidal wave of e-waste threatening the planet. Right to Repair legislation is desperately needed to level the playing field between the digital haves and have-nots.
Farmers already face this problem, with some turning to cracked Ukrainian firmware and sketchy backroom deals to obtain the software they need to repair equipment. And Paul Luiz, an expert diesel equipment mechanic, told us that he experiences the same problem trying to access engine diagnostics.
It’s time we call out the shroud of secrecy surrounding these tools for what it is: yet another strategy of planned obsolescence, aiming to force us into either unneeded product upgrades or paying the manufacturer’s inflated repair prices. If manufacturers won’t release the repair tools we need, then we’re just going to have to pass legislation forcing them to.
If you know more about AST 2, Samsung’s Must software, or other sly/secret diagnostic apps, we’re open to tips. I’m firstname.lastname@example.org, but we can move over to secure chat if you like.