A new report from iFixit today looks into a curious case of many iPhones and Apple Watches failing at a hospital, at the same time. At first the cause was thought to be an electromagnetic pulse, but further investigation revealed the issue was helium.
They mystery started when a new MRI machine was being installed at Morris Hospital, outside Chicago. Systems Specialist, Erik Wooldridge said that he started hearing that smartphones had stopped working in the building.
His first thought was an EMP caused the problem:
However, he ruled that out quickly as Android smartphones weren’t affected and the medical electronics in the hospital were working normally as well. The only affected electronics were 40 Apple devices.
After posting the issue on Reddit, Wooldridge heard that it could be related to liquid helium contained in the MRI machine. After more investigation, he discovered that separate from the new MRI installation, there was a helium leak in the hospital.
About 120 liters of liquid helium were vented into the building over five hours, which expands 750 times when going from liquid to gas. While most devices started working again, not all did.
iFixit’s CEO and founder Kyle Wiens, wanted to dig deeper to found out more.
But there are two problems with this idea: One, Apple isn’t alone in using MEMS gyroscopes—every phone has them. Why weren’t the Android phones affected? Perhaps there’s a bug in iOS that causes crashes when it gets faulty data from the gyro? But the bug impacted Apple Watches, too—and they run WatchOS. Additionally, iPhones earlier than the 6 weren’t affected. It seems unlikely that this was a new software bug that impacted both iOS and WatchOS.
Wiens finally landed on the CPUs clock, the oscillator. They are often made from quartz, but more recently Apple started using MEMS silicon timing oscillators to improve performance and increase operating temperature ranges.
Wiens also discovered that Apple acknowledges this problem in its user guides for iPhone and Apple Watch.
I was able to repeat his experiment in our lab. My iPhone 8 lasted about four minutes in a helium atmosphere before it shut off entirely.
Apple notes that affected devices may recover, but gives some specific troubleshooting steps like letting your iPhone sit for a week without charging it.
