Apple’s internal tests found that the iPhone 6 and iPhone 6 Plus are significantly more likely to bend than the iPhone 5S, according to information made public in a recent court filing obtained by Motherboard. Publicly, Apple has never said that the phones have a bending problem, and maintains that position, despite these models commonly being plagued with “touch disease,” a flaw that causes the touchscreen to work intermittently that the repair community say is a result of bending associated with normal use.

The information is contained in internal Apple documents filed under seal in a class-action lawsuit that alleges Apple misled customers about touch disease. The documents remain under seal, but US District Court judge Lucy Koh made some of the information from them public in a recent opinion in the case.

The company found that the iPhone 6 is 3.3 times more likely to bend than the iPhone 5s, and the iPhone 6 Plus is 7.2 times more likely to bend than the iPhone 5s, according to the documents. Koh wrote that “one of the major concerns Apple identified prior to launching the iPhones was that they were ‘likely to bend more easily when compared to previous generations.’”

Despite these findings, Apple publicly maintained that there were no engineering issues with the iPhone 6 and iPhone 6 Plus, but an internal review showed that engineering changes were necessary to prevent touch disease, according to court filings. In May 2016, a year-and-a-half after the iPhone 6 and 6 Plus were released, Apple quietly began reinforcing the part of the logic board associated with touch disease, Koh wrote.

This is a different engineering change than one noticed by a YouTuber in August, 2015.

In a service notice published in November 2016, Apple said that touch disease happens only after iPhones are “dropped multiple times on a hard surface and then incurring [sic] further stress on the device,” which is the same argument it has made in defending against the lawsuit.

Bendgate

Soon after the iPhone 6 and iPhone 6 Plus were released in September 2014, several customers said that their phones bent easily. Those cases went viral, which caused Apple to release a statement that said the phones were structurally sound: Apple “perform[s] rigorous tests throughout the entire development cycle including 3-point bending, pressure point cycling, sit, torsion, and user studies. iPhone 6 and 6 Plus meet or exceed all of our high quality standards to endure everyday, real life use.”

That news cycle died, and “Bendgate” went away for a while. But in early 2016, many iPhone 6 and 6 Plus devices began to exhibit symptoms of “touch disease.” The phones’ screens would have a flickering gray bar at the top, and the touchscreen would stop working entirely or would work intermittently. Independent repair experts found that this was caused because the “Touch IC” chip, which translates a user’s touch into digital signals, became partially unseated from the phone’s logic board. Many independent repair professionals who specialize in microsoldering told me that they believe the problem is caused by flexing or bending associated with normal use, such as taking the phone out of your pocket and putting it back in.

"It's absolutely a problem in the design. End users are not doing anything to cause this besides using the phone normally," Mark Shaffer of independent repair company iPad Rehab told me at the time. "Really all you can do is avoid any activity that would cause the phone to flex. Don't drop it, definitely don't put it in any case that requires you to apply force to the phone to get it into and out of the case. Don't put it in your back pocket, don't put it in your front pocket if it's a tight pocket. Actually, don't put it in any pocket."

The Lawsuit

The problem became widespread, and eventually a class action lawsuit was filed against Apple, which has been ongoing for more than a year. As a result of discovery in that case, Apple was required to turn over its internal testing documents and reports to the plaintiffs’ lawyers. Those documents remain under seal, but Koh made some information from them public in an opinion published this month.

Know anything more about touch disease? Contact the reporter securely on Signal: 301-412-7324. Motherboard also has a SecureDrop.

Beyond noting that the iPhone 6 and 6 Plus were significantly more likely to bend than their predecessor (Apple described the bending as “expected behavior”), Koh wrote that Apple made engineering changes to the phone a year-and-a-half after it was released in order to prevent touch disease.

“After internal investigation, Apple determined underfill was necessary to resolve the problems caused by the defect,” Koh wrote, referring to an epoxy used to stiffen the logic board. “Apple had used underfill on the preceding iPhone generation but did not start using it on the [touch disease-related] chip in the iPhone 6 and iPhone 6 Plus until May 2016,” after millions of iPhones had been sold.

Apple did not publicly acknowledge touch disease until November 2016, after widespread news reports about the issue, including in Motherboard. Apple announced it would replace touch-diseased phones for $149; it had previously charged $349. In its public announcement, Apple did not acknowledge that it had recently made engineering changes to the iPhone 6 and iPhone 6 Plus.

In a court filing in the class action case, Apple’s lawyers wrote that its “rigorous and comprehensive reliability test data proved that enclosure bending and twisting cannot cause the issue unless the phones had already been repeatedly dropped on a hard surface,” but this has been disputed by the plaintiff’s expert witnesses. Apple has argued that those witnesses aren’t experts in part because they hadn’t “reviewed” Apple’s internal tests.

Koh denied the plaintiffs’ attempt to be certified as an official class because the plaintiffs could not present a sufficient model for being paid damages in the event that they win. The case is ongoing because the plaintiffs have signaled that they intend to file a motion for reconsideration or an appeal.

In her opinion, Koh notes that Apple “opposes Plaintiffs’ motion for class certification on nearly every front.” Apple argued that the plaintiffs expert witnesses aren’t experts, that one plaintiff should be excluded because his employer bought his iPhone for him, and that consumers could not have been uniformly exposed to any alleged misinformation or lies of omission because Apple keeps its iPhone boxes in the back of the iPhone store, where customers aren’t allowed.

Apple “states the iPhone 6 and iPhone 6 Plus boxes were kept in the back of Apple Stores and were not visible until they were brought out so a customer could buy one,” Koh wrote. “These points are not persuasive.”