Teardown: Apple MacBook Pro 2018 Touch Bar Keyboard
Image credit: Apple
Apple’s ‘butterfly’ keyboard flaps its wings with predictable results.
This month’s Teardown takes a detour. Rather than an entire product, it looks at a system within one: a keyboard. Then, as much as it considers the design, the politics surrounding it are arguably as important.
Apple followers will be familiar with the controversy surrounding the butterfly keyboard. Here is the background for everyone else.
First seen on 2015 MacBooks, the butterfly mechanism replaced the scissor joint used to register when keys are pressed. It allowed Apple to reduce the thickness of the keyboard by 40 per cent. Another trip to WeightWatchers for the laptop.
However, a problem became increasingly apparent to many users. The new mechanism was susceptible to contamination. Teardown experts, including iFixit, confirmed this fear: a single grain of dust or sand could get wedged in a butterfly mechanism, causing the specifically related function to stop or repeat uncontrollably, or disabling the keyboard entirely.
It got worse. The keyboard sat within a wider design where other slimmed-down elements and globs of glue made it hellishly difficult to swap out a malfunctioning key. That applied whether the faulty laptop was taken to a Genius Bar or an independent repair shop. Often, the only solution was to replace the entire ‘top’ assembly – laptop, track pad, battery and more.
This June, Apple publicly acknowledged the problem and extended the warranties on laptops it had already sold that incorporated the butterfly keyboard – nine of its higher-end MacBook and MacBook Pro models. Anyone who had already been charged for a keyboard repair was offered a refund.
The company also said that it had enhanced the mechanism inside its 2018 MacBook Pros. So, how well has it done there?
An iFixit teardown of the keyboard within the latest 13in MacBook Pro found that Apple has made the keycaps thinner and thus easier to remove (1.25mm vs 1.5mm). The company has also redesigned the space-bar mechanism because it was proving particularly vulnerable.
The main advance, though, comes under the keycaps. Each butterfly is now surrounded by a silicone layer in the form of a single die-cut sheet between the cap and the joint. In a pending patent, Apple describes this as “a guard structure coupled to the keycap operable to direct contaminants away from the movement mechanism”.
The iFixit team subjected the overcoated keyboard and its predecessor to a number of comparative tests. In test one, they sprinkled fine fluorescent blue powder on the keys and typed away. After the first pass, “The third-gen  keyboard routes most of the powder towards the edge of the key and away from the delicate butterfly mechanism. Last year’s mechanisms don’t fare so well.”
However, sprinkling more Smurf dust “pushes glowing dust past the membrane’s not-infallible defenses and onto the dome switch”.
The team then moved on to The Sand Test of Doom. It sprinkled these larger granules on the keyboard and then typed for a minute. “We don’t even have to lift the keycaps off to realise that something is wrong. A few keys have seized up!” iFixit says. “Prying the keycaps off, we find that grains of sand have invaded through the corner perforations in the membrane and jammed the butterfly mechanism.”
Rather than slamming the redesign, iFixit acknowledges: “The silicone membrane adds a significant degree of ingress resistance, but falls short of being fully dustproof.”
Progress, then? Well, of a kind. It is here that politics take over.
Apple is notorious for making its devices difficult for others to repair. There has been some Schadenfreude over the butterfly keyboard having hoisted the company with its own petard. But this philosophy still seems dispiritingly in place.
When iFixit dug deeper into the new assembly’s design, it once more encountered plenty of glue and rivets: “Apart from the improved keycaps, this keyboard design is still pretty lacking in serviceability. The sheer amount of disassembly required... makes replacing a failed keyboard seriously impractical.”
That was in the summer. As we have moved into autumn, things have become even more dubious. In October, the MacRumors and Motherboard websites published evidence that Apple has taken additional software-based steps to keep others out of its machines, including owners.
In a leaked document and associated presentation for internal repair staff and official partners, Apple warns that hardware products running the T2 companion chip – recent MacBook Pros and iMac Pros – will be bricked if various repairs are not finished by running an official diagnostic tool, the Apple Service Tookit 2. “Failure to perform this step will result in an inoperative system and an incomplete repair.”
As you have undoubtedly guessed, the MacBook Pro repairs covered here include any to the ‘top’ of the product, including the keyboard.
Apple’s silicon designers have for some time been integrating multiple standalone components into co-processors such as the T2. The T2 incorporates security features, chiefly a Secure Enclave that enables secure boot and encrypted storage. There is some justification for keeping outsiders out.
Given the controversy that has dogged the butterfly keyboard, the move seems unusually provocative. There is Apple’s ‘history’ on repairability. Coming up to date, class action lawsuits are now swirling around earlier implementations of the mechanism.
And then there’s this. One reason many people buy Apple products is their durability. What will happen if Apple decides in a few years’ time to no longer support these models? Or, if the justification really is security, is the company now planning to support T2 machines forever?
After all, a legacy device connected to a network that is opened up to outside repair becomes a security threat, if you push Apple’s argument to its conclusion. On this point, Apple remains silent so far.
This takes us a long way from keyboards, supposedly one of the most mature aspects of design. A butterfly has flapped its wings to potentially spark a storm over issues of not just built-in obsolescence but also the security obligations of tech companies in an increasingly connected society.
Apple could have just ring-fenced keyboard repairs – it’s not like it didn’t know it had a problem. Interestingly, the patent on methods to prevent contaminants entering keyboards was filed in March, three months before the company formally recognised the keyboard issue.
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