XIAO with CircuitPython Runs but No Longer Mounts After Solder

Hello –

Had this experience twice, so I must be doing something to annoy these XIAOs. Sorry if I’ve missed something obvious.

Each time, the XIAO mounts the circuitpython volume and works fine until I solder pin headers. Then after soldering the pins (with nothing attached), the python scripts still run but the volume won’t mount when plugged in to USB. Strangely, if I reset to reprogram (where it mounts as ARDUINO), that actually works/mounts (but reflashing doesn’t fix the issue).

What could I be doing wrong in soldering these pin headers to cause such a weird specific issue?


Are you using a small pencil type soldering iron ? Maybe try grounding it to the board.