Posted on November 22, 2014 at 18:50Short-circuits would tend to be caused by solder, incorrect orientation of the part, and circuit design/fabrication failures.
More than one board?
An unprogrammed part is going to have the majority of it's signal lines in input mode, it will crash almost immediately as there is no valid code to execute. The run something you'd need to strap BOOT0 so it enters the System Loader.
