title_body: My ESC in my stack just randomly exploded, any ideas why? I was casually flying my drone and my ESC board in my stack let out the magic smoke, and then fell from the sky randomly. I hadn't changed any tuning settings, and the stack was only ~3 weeks old. I am using a Mamba F405 MK2 stack, and the Flashhobby Samguk WU 2206 2700Kv motors. As far as i am aware, the Flight controller portion of the stack still works, but the ESC board is dead. The tune was essentially stock, except for modified serial port configuration.
  What could have caused it to explode, and what should I do?
upvoted_answer: From your description I assume that the ESC in the stack blew up, not necessary the FC. This makes most sense as that is the part where the biggest currents are flowing.
  Check if the electrolytic capacitor on the battery connection of the ESC still is properly connected as that absorbs the voltage spikes your motors generate during flying. If that capacitor is loose or located too far away, the voltage spikes can destroy the FETs on your ESC and you will burn up the ESC and the motor connected to that ESC.