Burned ferrite element between USB shield and ground pin on Teensy 3.1

[corvusandcolumba]

The blue smoke has escaped my Teensy 3.1. Looking at the schematic, this appears to be a ferrite element between the USB connector shield/ground pin, and the Teensy ground pin.

What circumstances would cause this component to burn out? This has worked perfectly for months, and now the burnout after disconnecting and reconnecting USB.

The Teensy 3.1 is connected to a computer via USB, receiving frames from the Movie2Serial, which it then displays out to a large RGB LED array.

Can the ferrite element be replaced? What happens if it's not there at all, or shorted across?

 

[PaulStoffregen]

What circumstances would cause this component to burn out?

Accidentally touching a power line to the USB connector shell or shield.

Can the ferrite element be replaced? What happens if it's not there at all, or shorted across?

It's not critical. Teensy will work without it, perhaps with extra radio frequency noise if the cable acts like an antenna. But it should be grounded on the computer side, so even then, it's probably not a big problem.