I default to skepticism on this sort of explanation, especially when it involves Apple and third-party repair.

Of course, it might be possible to devise a very sophisticated attack using the screen's hardware interface and Face ID as a vector. If the iPhone was a security-hardened specialty device, I might find that to be a valid reason. It isn't; it's a consumer device, and one that's not terribly hard for sophisticated attackers to compromise, e.g. https://www.wired.com/story/apple-imessage-zero-click-hacks/

Another scenario I can imagine is a charge controller reducing the maximum charging current as the battery ages based on information stored in the controller's memory, which would be incorrect if the cell is replaced. Of course, it would be unusual to replace a cell with one in worse condition, so it would also be surprising for that to be a safety concern.

It isn't, but there are some controller circuits that switch off permanently if the voltage falls out of range, making changing cells more difficult.

1. The MITM hardware could be installed into the screen that's already paired with the iPhone, so the serial check wouldn't help

2. The MITM hardware would make the screen look non-genuine regardless of serial, so the serial check wouldn't be needed

It’s not just a warning. Functionality is flat out disabled. Swapping parts between 2 iPhone 13s boinks them.

I pretend to be a security expert on TV; and I fully support the decision to disable face id when there might be a hardware mitm attack. But there's options available to Apple that allow you to have security and 3rd party support.

But they're clearly still making decisions that obviously obstruct user choice. And it's dishonest to pretend otherwise.

ps. I don't think you're being dishonest, you're clearly explaining the rational. My issue generally is the apologists who use these arguments without context, and pretend there's no other options.

That’s the messaging from the manufacturers which is a big lie IMO. You can validate keys or signatures and give a warning for non-genuine parts. The only reasons to disable features are to prevent competition and, ultimately, to cheat the customer.

Modern batteries integrate the charge controller with the cells, this allows to track the cell life and it allows the management of the chemistry.

Even small changes in chemistry require modifications in the charging algorithm. The only real solution for managing that is bundling the algorithm with the cells.

Setting the wrong configuration can definitely blow the cell up, or cause swelling.

Source: I did blow some cells while designing a battery pack for a portable device

Lithium-ion cells are one of the easiest to charge - there's minimum and maximum voltages, and a maximum charge current. Simply limit charge current to the maximum until the cell reaches its maximum voltage, and then wait for the current to drop until it's nearly 0.

Of course, exceeding those limits at the upper end certainly can result in flames, but it's seriously not that hard to charge a cell. But people like to spew plenty of FUD about "complex algorithms" and the like, because the companies who make the ICs stand to profit from that.

Source: I have also worked in electronics on battery-powered devices.

Yes, TI makes money when people use their battery management ICs with fancy cell monitoring, but I don’t see a lack of price pressure on those ICs. If manufacturers could implement the same features with a less complex, less expensive design, why would all of the modern battery systems, even in competitive sectors like consumer/retail electronics, integrate battery monitoring with the cells?

I don't think fast charging is a good idea anyway because it wears out cells faster, but that's another rant...

so this only concerns 3rd party repair shops or individuals who dont want to pay apple to replace their screen.

Another example - Volvo(and pretty much every manufacturer) says in their warranty terms that the warranty is only valid if the car is serviced annually at an authorized Volvo garage. They can say that, but the law in EU clearly states that you can have the annual service done at any vat-registered garage, and as long as "equivalent" parts are used, the manufacturer cannot deny you a warranty claim based on having the service done outside of their own approved dealership. Their own terms and conditions do not and cannot override the law.

The same law applies in US, this isn't some EU exclusive thing.

Also, this question applies in general whenever a company doesn't obey the law and your consumer rights - vast majority of the time, they do. But in case they don't you have solicitors, ombudsmen and yes, eventually, courts. It's rare that it gets that stage though.

1) have the car serviced outside of the main dealership network and the manufacturer is not allowed to void your warranty due to this.

2) fit aftermarket parts, and the manufacturer is allowed to void your warranty only if they can prove that the part contributed to the fault.

The whole conversation started by me saying that with cars, you can buy original OEM parts without having to obtain the blessing from the manufacturer - with Apple(and other electronics makers) you can't.

>>That still sounds like a lot of work for the potential savings of a few hundred dollars on repairs and parts.

I don't know why you assume this is any work, you just have your car serviced elsewhere, if any warranty work comes up then you just say "I had the car serviced at a VAT-registered garage, as allowed by the statutory consumer rights". Done, works 99/100 times. Do some dealers try to wiggle out of it anyway? Sure. But dealers try to wiggle out of warranty repairs even if you have done everything "by the book" anyway. That's just what they do. In that case you also have to either start involving experts/solicitors/courts to actually make the manufacturer honour their promise to you. Whether it's worth it to you or not, is a different matter entirely.

‘2) fit aftermarket parts, and the manufacturer is allowed to void your warranty only if they can prove that the part contributed to the fault.’

In the case of electronic products, we don’t assume things that things that look the same, perform the same.

An aftermarket iphone screen for example could even be from literally the same assembly line but perform so poorly that nobody reasonable could expect Apple to uphold their warranty on a phone with it installed. That’s why QC testing exists.

All other differences can be derived from that basis.

logic only a fanboy would dream up. I'm sure the same excuse would be given by fanboys if apple shipped a car and somehow managed to make the windows unreplaceable except by specially signed apple glass.

Unless Apple itself wasn't opting for crap battery suppliers