The End of Parts Pairing? Almost.

iOS 18 dropped on Monday, with a brand new feature we’ve been anxiously anticipating: Repair Assistant. Apple is finally delivering on their promise to make their repair software available on-device (though it requires Wi-Fi), starting with iPhone 15, iPad Pro M4, and iPad Air M2 owners. So of course we had to check it out. 

Our initial test results are in—and we appreciate what Apple is trying to do. But for now, it’s undermined by a very buggy experience.

History of a Closed Ecosystem

We’ve been calling on Apple to support DIY repair with on-device software since they started selling parts in 2022. For the last two years, if you bought parts through Self-Service Repair, you could only complete the repair via an over-the-air chat or call with Apple support staff. The person on the other end would go through Apple’s repair software to pair your part with your Apple ID, requiring your IMEI, your invoice number, and your agreement to some invasive terms.

If you didn’t do that (or if you were using a part you didn’t buy through Self-Service Repair), you could expect a whole host of problems. In the iPhone 15, repair without access to the chat assistant resulted in function loss for a half dozen parts. We’ve railed hard against these parts pairing problems, and this year, Oregon and Colorado both passed Right to Repair bills that will limit the use of parts pairing within the next couple of years.

When Apple announced in April that they would make changes to their parts pairing system by the end of the year, we didn’t think the announcement went far enough.

We were glad to hear that they intended to open up parts calibration to original parts, even those not bought through Self-Service Repair. We loved the idea that Apple intended to open up its repair software to users—and we hoped it would be available on-device. 

And we were thrilled when, in a follow-up white paper published in June, Apple clarified that with iOS 18, they would stop disabling True Tone and battery health for third-party parts. 

Still, we suspected that Repair Assistant would not offer the opportunity to “finish repair” with third-party parts. We wondered whether it would address other devices limited by parts pairing (turns out: iPads, yes. MacBooks, no). And we were concerned about the announcement that Apple intended to extend Activation Lock, a feature that has had problematic side effects for the recycling industry, to individual parts. 

Refurbishers Hate Activation Lock

Activation Lock—and the similar systems on other phones, like Samsung’s Reactivation Lock and Google, Motorola, and LG’s Factory Reset Protection Lock—remains the biggest barrier to reuse of secondhand devices. When it works as intended, it can reduce the incentive for theft. But all too often, it ends up sending working devices to the shredder, which is a huge waste of materials and energy, and contributes to greenhouse gas emissions.

The root of the problem is that people aren’t accustomed to disabling a software lock when they sell or donate their devices. Refurbishers and recyclers receive mountains of phones and laptops that can’t be reused, even though they’re in perfectly good condition, because the device’s owner forgot to turn off their theft protection. Extending Activation Lock to individual parts worsens the problem dramatically.

MacBook refurbisher John Bumstead says the extension of Activation Lock means that

“You cannot use an Activation Locked device as a parts machine, as every single part within the device has been condemned to death. Activation Lock and parts pairing are now working together for the greater evil. And Apple is spinning this as a positive because they are allowing the pairing of some unlocked used parts (of which there are very few).”

As Paul Roberts of Fight to Repair puts it, “The practical consequences of that could be devastating for small, independent repairers.”

OK, so in theory, there’s a significant rub. But how about in practice? How does the system fare?

Rubber Meets the Road

Two iFixiters put the system to the test—Teardown Technician Shahram Mokhtari and Repairability Engineer Carsten Frauenheim. They each took two iPhone 15s (Shahram used two iPhone 15 Pros, and Carsten used two vanilla iPhone 15s) and swapped their logic boards to simulate a replacement of every part in the phone. This is the procedure we have used to determine the extent and severity of parts pairing in new iPhones.

Shahram’s Experience: Boot Loops Galore, and Face ID Disabled

Shahram began with both iPhone 15 Pros still on iOS 17.1, then swapped a logic board from one phone into the other. The phone booted fine, with all the parts pairing issues we’ve come to expect: unknown part warnings and pop-ups for the battery, screen, and so on. A missing “battery health” indicator. No “True Tone” option.

He then updated the phone to iOS 18, at which point all the “replaced” parts were listed under Service History and an option was provided to restart into diagnostic mode to finish repairs. 

That’s where things started to go wrong. The phone failed to restart twice due to a “network error.” When it successfully restarted, it identified all the “replaced” parts, prompting calibration for several, with an error for Face ID (as expected). Shahram started with camera calibration, but instead of initiating calibration, the phone restarted. 

He tried again and again, and got stuck in the same loop—calibration attempts would just reboot the phone. When he’d hit “finish repair” in Diagnostic Mode, the button would just bounce him back to the “Diagnose or Repair” screen over and over. The only option available to reboot was “exit diagnostics.” 

When he replaced the camera with the camera paired to the phone’s “new” logic board, the Face ID repair prompt went away. However, the front-facing camera no longer worked, and Face ID was disabled entirely. Shahram was presented with a link to a webpage prompting him to take the phone in for service.

Meanwhile, the other calibration prompts continued to send him on an endless series of boot loops.

Shahram was lucky that he had the ultimate fix up his sleeve—putting the original logic board back in. When he did that, the boot loop stopped. Upon loading, the parts replacement history went away. The “finish repairs” option went away. He was left with a phone that showed no obvious record of its brain swap (and re-swap).

But of course, most folks doing repairs won’t have the opportunity to just put the device back into its original state.

“I’m going to call this the William Wallace update,” Shahram said, referencing the Scottish freedom fighter made famous in Braveheart, who remained committed to his freedom even while being brutally executed. “It’s freedom from parts pairing but at a terrible price.”

Carsten’s Experience: “More Good Than Bad”

We needed to see if we could replicate Shahram’s experience. So Carsten tried again, with some different parameters: He used vanilla iPhone 15s instead of Pros. He updated both to iOS 18 before doing the logic board swap.

At first, it seemed like deja vu all over again: All the parts showed up in service history, prompting him to finish the repairs. When he tried to go through the system, he got repeated network errors. 

The third time, the phone restarted, but did nothing during calibration, booting back into native iOS as if nothing happened. The fourth time, it restarted and landed on a white loading screen indefinitely.

Then, Carsten exited diagnostic mode and tried changing Wi-Fi networks: The iFixit office has one network that prompts a log-in portal and another that doesn’t. Carsten hypothesized that the diagnostic mode wasn’t capable of navigating the log-in portal (which would explain the white loading screen), so he tried switching to the other network.

This time, configuration worked as expected: the back glass and rear camera both had green checkmarks of success. Face ID had a yellow caution icon, and display and battery were both Activation Locked to an Apple account (curiously, the same Apple ID was the owner of both phones). When he logged in to authenticate the repair, the Activation Lock warning went away, and the display and battery both unlocked.

Although Face ID showed that it needed calibration, going through the “finish repair” process provided no option for it—just errors like “This part is not functioning as expected.” On top of that, when booting back into iOS 18 and using the phone normally, the selfie camera didn’t even work, just displaying a blank image in the camera app.

“It looks to be set up such that this is supposed to work eventually,” Carsten explains, “but Apple hasn’t flipped the switch to enable Face ID functionality on camera swaps yet like they suggested they would at some point in 2024.”

Like Shahram, Carsten reinstalled the phone’s original logic board and found the same result: No service history, no camera issues. He tried swapping just the selfie camera, to see if anything would behave differently. But, as with the full logic board swap, he was again unable to calibrate Face ID, and the selfie camera was still unusable.

Carsten’s take: “Repair Assistant works well—and the end result is really cool—but it’s decently buggy in this initial release as Apple continues to seemingly deprioritize repair. I’m looking forward to when they enable Face ID swaps and squash the obvious bugs.”

In Short: Yay for On-Device Repair Software—But This Is Unacceptably Buggy for Now

We want to emphasize how happy we are to see Apple releasing a user-oriented version of its parts pairing and calibration software. This change has been a long time coming, and it’s overall a boon for the repair world. Independent shops should be able to harvest original Apple parts (as long as they’re not Activation Locked, which is a significant exception, refurbishers say). People will have a history of repairs done on their devices, which can improve resale value.

We love the greater transparency in the user experience of repair. Instead of vague persistent “unidentified parts” warnings that have tended to scare users away from repair, part information is buried in settings and “not pushy,” Carsten pointed out. The new system presents repair history in a way that is, he said, “more informative than scary.” 

But this current release of the tool is unacceptably buggy, and we have to recommend you wait on this software update for now, if you’re going to do any repairs. In fact, you might want to wait on this one in general—Apple just pulled iPadOS 18 after it bricked a bunch of tablets, and another bug in Messages is causing repeated crashes.

Good energy, Apple, but this one ought to go back in the oven. We’ll have to test again when Repair Assistant is more fully baked.