Psu 24 pins problem

[Obey3F]

In my psu 24 pins connector there's one pins that didn't exist, is all motherboar like that?

 

[jimthenagual]

According to C12Friedman here
There used to be a white -5v wire there, but they are no longer used so they simply take them out now.

 

[hunter315]

The -5V pin hasn't been a part of the ATX spec since about 2003. Your 24 pin connector should be missing a pin.

 

[Dark Lord of Tech]

(Optional - Removed in ATX12V v2.01)

http://pcsupport.about.com/od/insidethepc/a/atx-pinout-24-pin-12v-psu.htm

Look at # 20 on the list.