I went with the 4 pin Noctua's. First attempt everything worked fine. Then after reboot, I noticed the oscillating sound that a previous poster described, it was very quiet but it was a very subtle annoyance, they would hum slightly louder and slightly lower, and the frequency of the oscillation would speed up between louder and lower. I don't know how to best describe it, but it would rev up and then rev down, similar to like a car's engine climbing and descending hills. It still overall was very quiet compared to the normal jet engine sounds, but just seem annoying, and would catch my attention.
So... I clipped I think the PWM wires. When it boots up, all lights are green, then eventually the lights turn red. I think its a very similar issue to yours, PSU reads ok, but the 4 fans spit off the error. In the WebGui it reports fans are fine temps are fine. I can't recall if the error was bad RPMs or not. The only thought I had was maybe faking it out by running the pwm wires to ground or something, like take all 4 clipped wires and just push them to one gound wire. I left it on for like an overnight and temps read ok. Overall after taking it apart 2 times, I just said forget it, it works, it's not overheating, so it shows red a red light, it still works OK, everything connects and links up, what's the big deal let the system complain, its not like the part is actually failing which I kind of think thats what the alarms are there for...to alert you to a stock part failure, not my crazy modding. My other thought was if it got so bad, I'd pick up a spare fan assembly and PSU, and just hot swap em out back to factory if I ever put it under heavy load. I hoped everything would light up green and stay green, but I'm not going to let a red light ruffle my feathers when the thing keeps on working fine.
