Static discharge and thumbstick data?

First, you are writing of some sort of casual static discharge where the thumbdrive is in the current path. That would be unusual enough unless you slid across a wool carpet and then used the thumbdrive to ground yourself.

But, I expect you would need something on the order of a static generator to make enough current to actually do damage.

Try this: Purchase a very cheap thumbdrive, and try to wreck it via static. You should be reassured by the results.

Peter Wieck Melrose Park, PA

I assume an old SD card would make a reasonable stand-in. I'll dig out an old ion-generator and have a go.

An SD card is NOT a reasonable standin. The USB connector shell is a Faraday shield, which SD lacks. The finger contacts for power and GND of a USB connector are the longest (most likely to engage first), but all SD pins are similarly accessible. USB data goes through a differential transceiver, but an SD card sends and receives single-ended logic signals. A 'dead' SD card may be hard to detect, unless your reader can exercise all its modes of data transfer.

As far as electrical properties of the connector are concerned, only the power and ground pins have similar properties between SD and USB (and those are NOT the static-sensitive pins).