HOW TO: Quark Mod / LSP Conversion *PIC OVERLOAD WARNING*

[BrianG]

If it IS a cap, I'm puzzled as to why it smoked. Caps are either used to "store" DC or pass AC (depending on frequency). Neither application really lends itself to blowing unless you exceed the working voltage of the cap.

Is it possible that there was a metal shaving laying alongside the device shorting across both solder pads, and when you plugged in the ESC, that shaving acted like a fuse and incinerated? This would create a decent spark and deposit the vaporized remains of the shaving on whatever was close by making it look like the device is blown.