Sys Fan 1 plug problem.

tuesday0108

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I have my front case fan connected to the motherboard slot "SYS FAN 1"


The front case fan has LED lighting. The LED Light lights up when I plug it into the motherboard SYS FAN 1, but the fan blade doesn't turn. Infact it's moving slowly. Making one slight movement every 1 second. Almost like it's not getting enough power.

What is the issue with this? I just got a new motherboard three days ago and I just noticed this problem.
 

tuesday0108

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Hey thanks.

I have an HAF 932 case.

I just recently swapped out my old motherboard (G31T-LM2) for a new motherboard(Gigabyte 890GPA).

I didn't have this problem when using my old motherboard.



 

tuesday0108

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Yes when I plug it into the PSU it works just fine. It's that one sysfan 1 plug that doesn't work.
When I connect to the top fan to the PWRFAN plug works fine. Same with the rear fan connecting to SYSFAN 2.

It's weird because I didn't have this issue with my previous motherboard.
 
It's really weird, the LED fan use more power, but don't have sense that don't works fine, BUT the problem isn't the mobo because the other two fans work fine. So, I think that the fan needs more power and the connector of the mobo can't supply that power.
 

tuesday0108

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I think you may be right. The front fan is a 230mm fan with LED while the side fan is a 230mm no LED.


When plugged into the port the front fan LED lights up but fan don't spin. When I plug the side fan into the same port it doesn't spin either.

Does it take more power to spin a 230mm fan?
 

tuesday0108

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I used both the front fan(has LED) and the side fan (No LED) and they both don't spin.

I checked the bios and it shows the fan as being there but at 0 RPM.
 

tuesday0108

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Hmm, am I only supposed to plug a 4 pin to 4 pin? The 4 pin on the mobo has 4 pins, but it has a little notce that allows 3 pins to fit in (error proof method)
 
4 Pin plugs are PWM, or Pulse Width Modulation. The other method is voltage control (3-pin).

Quick Run down of the wires:
PWM:

1-12V in (constant, supplies power)
2-Ground
3-PWM signal in (sets speed depending on duty cycle)
4-Speed signal out (gives RPM of fan)

Voltage control:

1-Variable voltage in (controls fan speed and supplies power)
2-Ground
3-Speed signal out (RPM)

(Note, these aren't in the correct pin order, I was too lazy to look that up).

Most 4 pin motherboard headers are designed so they can do both. In the BIOS, where fan control is, there often is a setting for PWM control, voltage control, or auto. If not, it may automatically select or be only one or the other for each port.