Fan problem at startup. NF-F12 on Asus z77

Hello

I got myself a Noctua NF-F12 for my cpu cooler, and every time I start my system a cpu-fan error pops up, and then I go into the bios, and exit without making any changes, and then the system appairs to be fine.

My system is  the i7 3770k on an asus p8z77-v deluxe board with kingston memory.

I have the fan running at 25% in fan-expert 2.

Try plugging the fan into a different fan connector on your board. I have 2 of those fans working on my cooler in push pull with no problems.. It could be your fan connector OR the fan.. maybe you got a defective fan... but it doesnt sound like it since it works after a restart or what ever.

Also, I have had a problem with conflicting fan controller software. if you have multiple monitoring software up and running, then it can cause problems. I had a similar problem with aida64 running at the same time as the asrock extreme tuner. The temp sensor was reading 0 or -2c and the fans just turned off. Now I made it so aida64 starts manually and not with windows, and that seems to have fixed the problem.

That's because fan is 3 pin but MoBo is expecting CPU fan to be 4 pin. Disable 4 pin feature in BIOS and you won't get those erros anymore. 

The difference is 4 pin uses PWM (pulse-width modulation) and 3 pin uses voltage control.

The PWM allows for better control over fan also allows fan to work on lower rpm's.

Thank you :)

I connected my back-fan to the CPU-fan-header on the MB and the NF-F12 to a different fan-header, and now it works perfect.

Thank you for taking the time to answer, but the Noctua NF-F12 is a PWM fan, that was one of the reasons I bought it.