Motherboard not recognizing new 4-pin fan

[root1]

So I replaced my Intel 3570's stock fan with an Arctic Freezer 7 PRO Rev.2 heatsink and fan. Install went fine.

When I boot my pc, the BIOS does not recognize the fan is spinning and the fan IS spinning. It sais fan has "slowed or stopped" though I can see the fan clipping right along. The stock fan was of course a 3-pin and the new fan is 4-pin. The CPU fan header is a 4-pin header.

Any one know why this board may not be recognizing the 4-pin fan on the 4-pin header? Board is an Intel DZ77GN-55K

 

[dtrunk]

odd thought; update bios? reset bios? mayb on first start-up it wants to remember the fan and since it is different, it's freaking out. i had a similar issue with this with another board, had to run the cpu fan off of a molex to 4-pin, and then use a broken fan to at least take load from the header (without the cpu header occupied the board wouldn't boot, but didn't recognize any working fan on the cpu header.)

PS: mayb the tach or pwm feature isn't setup? within the bios?

 

[root1]

Just did a prime95 stress test and the board does pick up the cpu fan once it kicks to high around 60 C. I think it's more of a board setting (this has the visusl BIOS) but just can't seem to find it. It IS running and seems to keep it cooler than usual so I guess I am happy at this point.

 

[dtrunk]

just look around the bios... something i found on intel's website.

"Under control mode, the options are manual or auto. Changing it from the default of auto to manual removes the two options of min and max duty cycle and replaces them with the option "Manual duty cycle %" ."

so it's in the bios, just figuring out where can be 1/2 the battle. also a google search for "DZ77GN-55K fan setting" shows a few forums and answers. you might also be able to use an app like speedfan.