I get that this is intended to be a general exercise in spotting schematic errors. But as someone who brought-up and debugged numerous complex power supply boards for mobile electronics, it seems to me the most important and useful bit of information is missing from this exercise: show me where the smoke came out!
I considered including the actual one page PDF I use for interviews in the post, but I didn't want to chance someone finding it online before they came into an interview with me.
But yes, the central point of the exercise is "show me where the smoke came out!" (It's a very, very dumb mistake. Nearly everyone I've spoken to has reasoned their way to it.)
The rest of it is to let people demonstrate what other errors they can pick out, or serve as fallbacks for the folks who don't find the magic smoke/component death failure.
