I recently finished my first quad and have been practicing flying. At the end of my session today, I tried one last take off, something went wrong (probably due to a faulty motor) and the quad flipped itself. Ouch :( Fortunately, aside from an FPV radio antenna there didn't seem to be any serious damage. I did a quick check to see if the motors still spun (they did) and was about to pack up for the day when the power to the APM went out, the ESCs started beeping, and the APM never came back, even after a reboot.
When I got home, I started debugging. The APM appeared fine when powered by USB. I plugged in the batter and tested the voltage of the ends of the APM power cable to the APM with a multi-meter but got nothing. I tested the base of the APM cable and got nothing. I tested the ESC power connectors, and all of those were totally fine (12+ volts). Strange! Thinking I maybe had a cold solder joint, I re-flowed the solder of the wires into the PDB. Still nothing. I then removed the APM power wires and checked the traces, still nothing. Totally stumped.
It seems that something something died inside my PDB. But I'm really curious what died and what the likely causes were (esp if I did something to contribute to it). The PDB is the standard 3DR Quad PDB. I use 20 AMP ESCs to 880kV motors. The battery is a 5800mAh 30C 3S Zippy LiPo.
I'll be greatful to anyone who can shed light into this mysterious happening.