This was down to something called "serialization" or "parts pairing," and it’s a tactic Apple is increasingly using to combat unauthorized repairs. If the digital serial number doesn’t match, the donor component can be rejected in a number of ways. And while Apple has proprietary software to approve new serial numbers within a device, third parties don’t.
Unlike the Face ID issue, this side effect is less pervasive and might be missed altogether by some owners, because it impacts an optional accessory: the Apple Pencil.
Those who get a third-party screen replacement on recent iPad Pros (5th and 6th-generation 12.9-inch models, or 3rd and 4th-generation 11-inch versions) may find that their Apple Pencil refuses to draw straight lines.
“We found with the newer versions of the iPad that when you put a new screen on, even if it's taken from another iPad, the pencil strokes don't work perfectly,” Ricky Panesar of iCorrect — an Apple repair specialist — told Forbes.
“They have a memory chip that sits on the screen that's programmed to only allow the Pencil functionality to work if the screen is connected to the original logic board,” he continued.
You can see what this looks like in practice in the video below. With the original (broken) screen, strokes in green appear perfectly. With an official display taken from another iPad, the red strokes suddenly appear slightly jagged. Finally, moving the microchip from the old screen to the new screen makes the blue lines appear perfectly again.
For Panesar, that’s a severe problem. “Apple are punishing you,” he told Forbes. “They're creating a monopoly where it means in the future, you have to go to Apple to have your device repaired.”
That’s typically significantly more expensive. Though Apple doesn’t have a "screen replacement" option on its repair estimates page, selecting "other damage" on the sixth-generation 12.9-inch iPad Pro brings up an estimated cost of $749.
“What this means for consumers is if you damage your iPad screen, you now need to find a specialist,” Panesar continued. “Repairs have to go through specialists and there are not many of us in the UK and there's not many of us globally.”
In other words, if your iPad screen breaks, don’t go for the cheapest option. Do your research, ask questions and make sure that everything is working before paying up. And if you're experiencing other issues with your Apple Pencil, check out our troubleshooting guide to get your Apple Pencil up and running again.