USB Debugging

Read the shared embedded contract and keep source/build, device and physical evidence separate.

Read USB diagnosis. Identify connector, data-capable cable, power path, native USB controller versus UART bridge, VID/PID, interfaces, serial identity and host OS. Record enumeration before and after the event; a changing port name is not necessarily a different physical board.

Separate no electrical connection, failed enumeration, missing driver/interface, port ownership and application protocol. Record descriptors, endpoint types, configuration and host logs with credentials/private serials redacted in public reports. Check D+/D- wiring, clock/PHY/VBUS expectations and power externally only against the exact board design.