Fan Header Connection - non standard header?

[Nicholas Peyton]

Hi all,

I have a non-standard motherboard I am using for a project:

What way round is this motherboard's fan headers - or how would I know what way to connect the fan connector? [See my explanation below]:


The header doesn't have the usual "insertion key" [bit of slightly double raised plastic] that the main motherboard brands always have for their fan header's).

I'm scared to switch the rig on. (yes, my project is ACTUALLY being held up by a mere fan header)!

I understand the motherboard fan header pinout will be:
1 - ground
2 - 12v(+)
3 - sense
4- control
But is that from 'left to right' or 'right to left'? (I've found images for both from google searches consisting of: "motherboard fan header pinout").


Pictures from different angles are below:
(Sorry have to post the URL's because the moderator wants me to post it on social media first then embed that image instead??? - why on earth would I want to post 3 images of a motherboard fan header on my Facebook profile)?!?!? Every time I come back to this site after a break it seems to have got worse due to some moderator's control. My privacy is important to me. (I don't want some nosey moderator checking my social media profile via an image I needed to embed).


right-click & select open in new tab

1

http://86.173.131.103/beechamcw2/wp-content/uploads/2021/09/1-scaled.jpg

2

http://86.173.131.103/beechamcw2/wp-content/uploads/2021/09/2-scaled.jpg

3

http://86.173.131.103/beechamcw2/wp-content/uploads/2021/09/3.jpg

Thank you, (sorry about the pictures/lack of).



Nick Peyton

 

[68Olds]

I am fairly certain the triangle indicates pin 1.

 

[Crimper]

@Nicholas Peyton

(Revised for clarity, still not very clear but this should be pretty straight forward. I wouldn't expect the fan to get cooked even if it were installed the wrong way; even without the retention guides, you want to be able to see the silver/gold pins facing 'up', through small holes in the housing/shell on the end of the fan cable. Photo 1 in your initial post illustrates the proper orientation. If you power it up with the fan connected just as in Photo 1, I really can't imagine that things wouldn't work as intended, so long as the fan is standard and not like a pull from a server/non-PC application.* *UNLESS the fan itself has a proprietary pin-out, you're good. Provide the fan make/model and board make/model for a thorough conclusion.*)

What you could do, is:
* Disconnect fans from board fan headers.
* Power on the board.
* Using a multimeter (Set to Direct Current), black/ground probe to the system chassis (or a common ground pin/terminal, such as those found in PCIe 6 or 6+2-pin female connectors, or a 4-pin Molex/Mate-n-Lok...), and then probe/check each of the 4 pins on the fan header until you find +12V.

If it's still not clear, peel the sticker back from where the wires/cables go to the fan's PCB. The PCB typically labels each wire/solder joint.

 

[mb194dc]

What board is this? Get the board diagram from google?

Maybe get a multimeter and check each pin to check where 12v is to be 100% sure?

Usuallly it's Pin No:
1 GND
2 +12V
3 Sense
4 Speed Control

I have a gigabyte board where it's actually VCC on 4 though on some headers...

 

[Nicholas Peyton]

Thanks for your replies guys.

68Olds - I share your opinion about the triangle indicating pin 1. (But not sure 'enough' to power the rig on)!

mb194dc - the board is this: btc79x5 (non branded Chinese board). The reason I am using it is because it has five 16x (full length) PCI-E lanes and I need as many full-length lanes as possible for a project.

 

[68Olds]

As mb194dc suggested, you need to power it up without fans connected & check one of the fan headers with a digital multimeter.

 

[Nicholas Peyton]

@Crimper, thank you as well - sorry for not mentioning you before (your post [believe it was your 1st] didn't actually show up straight away).