the BEC of my ESC burned out for some reason (really, with smoke) and since then my APM doesn't talk anymore, neither via telemetry, nor via USB. It is recognized by the PC as Arduino Mega 2560 and the com LEDs flicker but no data is coming through from the APM. Establishing a link also triggers a reset of the APM.
Besides the lack of communcations, the APM otherwise seems to work fine. It shows GPS lock after a while and I can arm it and spin up the motors. I didn't dare to test more, but ARM / Disarm and GPS works all ok, as it seems.
It just doesn't communicate anymore.
What could be the problem? A visual inspection of the PCB didn't show any obvious damages on the APM board, while one IC in the SBEC of the ESC bursted...