Hello @labubu ,
First, you should ensure the USB cable is functional and properly connected. Verify that the USB pins, jumpers on the STM32C0 board are correctly connected.
Is the USB driver installed correctly?
Check also if the USB VBUS pin is properly powered.
Verify that the USB descriptors (device, configuration, and endpoint descriptors) are correctly configured.
If you can provide more details about the hardware schematics or USB pin connections for your STM32C0 board to further analysis the issue.
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