Would ROFL except it made me sad.
your theory seems to be true though.. my one board with the dead die runs significantly hotter than the rest and that is with it hashing at 75%
can't see anything with the eyes that stands out, and while it hashes at 75% not really worth it to keep shutting things down to fudge with it for now
maybe RMA it when KNC gets out of the woods
me too have a completely dead die but all my fans were in place (i've checked while unboxing).
this happens for the two jupiters I own. (so one bad asic slot ech jup)
the common thing is that both the "flaky" asics are marked with a #3 stickers.
edit1: i've asked to hno (OrSoC eng) on irc channel it there's a relation between number on sticker and quality and he said a "weak one", but he didn't say everything he knows imho (and I can understand him)