158 days after I built my computer, the CPU fan that came with my SilverStone AR06 died (it could not spin fast enough to cool the CPU. Manually setting the fan speed to 100% wasn't helping). So, I bought a Noctua fan to replace it. 329 days later, my Noctua fan failed. The fan was working when I turned the computer off. The computer stayed turned off for a month. Now the fan will not spin. It barely spins when I power it up, but that's about it. I blew on it a bit, and rotated it myself before turning it on, which caused the fan to barely spin for a few seconds, before coming to a stop again.
There's not much to see, but here it is attempting to run when I turn it on: https://youtu.be/xwJGs7zjkYU
I tried a different fan header, but that didn't produce any different results.
I find it extremely unlikely that two fans would fail... especially a Noctua. At this point I suspect the motherboard might be to blame, but I'm not sure. Should I replace the fan yet again? Is the motherboard at fault? What should I do to further troubleshoot? I'm afraid to leave my computer on for too long (i7 6700k) without a working CPU fan. Am I just really unlucky?
Here I managed to get the fan to run extended (flipped the computer on its side): https://youtu.be/Qn6y1HWLkII. It's still definitely not spinning fast enough to do much.