Last month, we reported that Apple's "T2" chip would block repairs of Apple products, citing documents obtained by Motherboard. But iFixit got their hands on a Macbook Pro around that same time, and found that they could switch displays and logic boards without the T2 chip locking them out. However, users recently discovered that Linux won't boot on T2 enabled devices, and yesterday, Apple told the Verge that the T2 chip does block 3rd party repairs. So what gives? While Apple told The Verge that a logic board swap should require Apple authorization, they also said "Apple could not provide a list of repairs that required this or what devices were affected. It also couldn't say whether it began this protocol with the iMac Pro's introduction last year or if it's a new policy instituted recently." In the words of iFixit CEO Kyle Wiens, the T2 chip is "'a guillotine that [Apple is] holding over product owners," and is something that they could activate at any time via a software update. Apple confirmed to The Verge that the display assembly should not require the diagnostic tool, but it is unclear why iFixit was able to swap logic boards and still boot the machines. One possible explanation is that iFixit used components already validated by Apple, and the diagnostic tool may only be required for brand-new, unused components. iFixit speculates that the software could be a mechanism for checking that third-party repair shops are using the correct components and not overcharging customers and using cheaper parts to make money on the side. It could also be for calibration purposes. But O'Comb says that Apple may want to have more end-to-end control over how Mac computers are repaired, what parts are used, and how much those repairs cost the customer.