Custom Board RP2040 impossible to access through USB


I just finished a custom board using a RP2040 based on QT RP2040 PY designs. I tried to flash it over USB but the CPU is not recognized, even using MU editor (I developped everything using circuitPython and I would like to use the same configuration with my board ; drag and drop files is pretty convenient…)

I check all pins : voltage levels and pinout (including USB) is correct.

I tried to tie down RUN / CS of the flash but nothing changed

Is there a first flash to achieve using SWD ? Like for installing a kind of USB bootloader or anything ?

Anybody can help ?


I think you can share your PCB design of this product here:PCBWay Community:Your Home for PCB,Electrical Engineering & Electronics Community
Many experts hang around here. They may suggest what should be corrected in your design to make it functional.