Optiplex Desktops

2 Iron

780, CPU fan pin out

Anyone knows the purpose of five CPU fan pins? I need to connect a non-Dell fan which has four wires. Is there 12 V, ground, RPM and PWM as usual or there is some proprietary fan control in place?

Solution (1)

Accepted Solutions
8 Krypton

Dell sometimes swaps the wires around so that you will fry a dell fan on standard and the other way round.

It has 5 pins but only 4 wires are used.

Dell does not publish this. And some dells use standard wiring.

I believe this is correct.

YMMV

 

4pin PWM on 3 pin4pin PWM on 3 pin

 

Dell MB
Pin Number

Function

Dell wire color

Std Fan
Pin Number

Std Fan wire color

Description

1

Sens (TACH)

White/Yellow

3

Green

Sens (TACH)

2

+12v

Red

2

Yellow

+12v

3

Gnd

Black

1

Black

Gnd

4

PWM

Blue

4

Blue

PWM

5

Key

unused

 

 

  

 

 

DELL FAN WIRES AND COLORSDELL FAN WIRES AND COLORS

 

 


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View solution in original post

Community Accepted Solution
Replies (4)
8 Krypton

Dell sometimes swaps the wires around so that you will fry a dell fan on standard and the other way round.

It has 5 pins but only 4 wires are used.

Dell does not publish this. And some dells use standard wiring.

I believe this is correct.

YMMV

 

4pin PWM on 3 pin4pin PWM on 3 pin

 

Dell MB
Pin Number

Function

Dell wire color

Std Fan
Pin Number

Std Fan wire color

Description

1

Sens (TACH)

White/Yellow

3

Green

Sens (TACH)

2

+12v

Red

2

Yellow

+12v

3

Gnd

Black

1

Black

Gnd

4

PWM

Blue

4

Blue

PWM

5

Key

unused

 

 

  

 

 

DELL FAN WIRES AND COLORSDELL FAN WIRES AND COLORS

 

 


Report Unresolved Customer Service Issues
here

I do not work for Dell. I too am a user.

The forum is primarily user to user, with Dell employees moderating
Contact USA Technical Support


Get Support on Twitter @DellCaresPro


Diagnostics & Tools

View solution in original post

Community Accepted Solution

Thank you! I can't say I wasn't searching, but you saved my day. :)

I have an adapter thats exactly wired like this,
but I'm getting a Fan failure error when trying to use my Noctua PWM fans.
Any solution for this?

If you plugged them in wrong you have fried your fan sensors on the fan and perhaps on the board.

 


Report Unresolved Customer Service Issues
here

I do not work for Dell. I too am a user.

The forum is primarily user to user, with Dell employees moderating
Contact USA Technical Support


Get Support on Twitter @DellCaresPro


Diagnostics & Tools

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