Where is a system fan?

[scorpi141]

When i go to my BIOS and check the temperature of CPU & motherboard, it says System Fan: 0 rpm. I checked all the fans in my system and all of them work. Which one is the System fan? Is it possible that i plugged it to the wrong pin?

 

[Shooters]

It's probably for one of the fan headers that you're not using or for a fan that you may have plugged in but doesn't allow for RPM monitoring (two wires instead of three).

 

[slashDevSlashNull]

note:
Myself I have experienced the same problem twice. Once it was because the mobo was faulty in some way, it did not read the rpm whatever fan i tried. The next time I was using a very slow spinning fan and the particular mobo wasn't able to read such a low rpm, it simply displayed 0 rpm... (The fan was OK, it worked perfectly with another mobo that was able to read it's rpm.)

 

[Jeff7]

Plus, some motherboards have 3 or 4 fan headers, but only support RPM monitoring on two of them.