Sometimes hacking isn’t as much about building something, it’s about getting to the root of a particularly difficult problem. [Erik Wooldrige] was facing a problem like that. He’s a system specialist at a hospital near Chicago. Suddenly a bunch of iPhones and Apple watches were failing or glitching. The only thing anyone could think of was the recent install of an MRI machine.
Sure, an MRI machine can put out some serious electromagnetic pulses, but why would that only affect Apple products? Everything else in the hospital, including Android phones, seemed to be OK. But about 40 Apple devices were either dead or misbehaving.
It took some detective work, but they think they know what was the cause. The MRI machine uses liquid helium to cool its powerful magnets. Turns out the helium had leaked and over 5 hours about 120 liters of liquid helium vented into the air. Helium is notoriously hard to contain because, like hydrogen, it is a tiny little atom even by atomic standards. It also expands about 750 times when it turns into a gas, according to the post’s analysis.
Gathering more data, they found that many of the phones would eventually recover and that all the devices were at least an iPhone 6 or an Apple Watch. So even older iPhones seemed to be immune. Some speculated that the helium is small enough to get into the MEMS devices like the accelerometer or gyroscope that is in most modern phones and affect its operation. But why would that effectively brick phones? And why wouldn’t that affect most phones Android or otherwise?
The best theory — and it seems plausible to us — is that Apple stopped using quartz crystals for the phone’s internal clocks. Instead, they are using MEMS oscillators from a company called SiTime. Supposedly the MEMS oscillators are smaller and work better at temperature extremes. If the mechanical clock element got gummed up with helium, that would explain all the observed evidence.
[Erik Wooldrige] reading about the issue on Reddit, did an experiment where he subjected an iPhone to helium in a plastic bag. Granted, this is a lot more concentration of helium than the hospital probably got. but they also had five hours of exposure. In the video, below, you can see Erik’s phone stopped keeping time just after the three-minute mark on the video, eight and a half minutes of exposure.
It turns out if you read the iPhone user’s guide it reportedly says:
“Exposing iPhone to environments having high concentrations of industrial chemicals, including near evaporating liquified gasses such as helium, may damage or impair iPhone functionality. … If your device has been affected and shows signs of not powering on, the device can typically be recovered. Leave the unit unconnected from a charging cable and let it air out for approximately one week. The helium must fully dissipate from the device, and the device battery should fully discharge in the process. After a week, plug your device directly into a power adapter and let it charge for up to one hour. Then the device can be turned on again.”
Apparently, SiTime also is aware of this problem and says its newer devices are “impervious to all small-molecule gasses.” But they admit older parts were not immune.
Unless you spend a lot of time blowing up balloon animals, this probably won’t affect you. Still, we thought it was an interesting piece of detective work and one of those things that you might remember in a few years when you have some wacky failure in your blimp fleet. Of course, we were supposed to be running out of helium, so if that were true, this problem would eventually take care of itself.
from iphone hacks – Hackaday
