Some devices use MEMS oscillators instead of crystals, which has the bizarre side effect of making them allergic to helium: https://ifixit.org/blog/11986/iphone

Some devices use MEMS oscillators instead of crystals, which has the bizarre side effect of making them allergic to helium: https://ifixit.org/blog/11986/iphones-are-allergic-to-helium/ https://ifixit.org/blog/11986/iphones-are-allergic-to-helium...