Case fans: Are 3% of them lemons ?

[MrDigital]

Out of hundreds of cases and separate fans, I've never had a dead fan. Lots of noisy fans, but none dead.

You mean you've never had a DOA fan or just one die in general? Seems like you have amazing luck. I've had one DOA and quite a few (<10) die over the years. None personally but various business machines.