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Proper use/allocation of ports/pins on MB

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#1 blitzjg


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Posted 30 July 2018 - 10:43 AM

Hello everyone,


I built my own computer from a build that was recommended to me at the time, probably about 7 years ago. I really have little experience, but was able to stumble through it and put it together and it has been working fine essentially the entire time.


Last night I opened up my tower to check on some hardware and investigate why my front Chassis USB ports were not working.  Long story short the different pin slots and connectors had me somewhat lost and concerned parts were not connected in the most efficient fashion.


The motherboard I am working from is ASUS P8Z68-V PRO/GEN3 LGA 1155 Intel Z68 HDMI SATA 6Gb/s USB 3.0 ATX Intel Motherboard with UEFI BIOS which is said to have:

2 x CPU Fan connector(s) (4 -pin)
2 x Chassis Fan connector(s) (1 x 4 -pin, 1 x 3 -pin)
2 x Power Fan connector(s) (3 -pin)
1 x S/PDIF out header(s)
1 x 24-pin EATX Power connector(s)
1 x 8-pin ATX 12V Power connector(s)
1 x Front panel audio connector(s) (AAFP)
1 x System panel(s) (Q-Connector)
1 x MemOK! button(s)
1 x TPU switch(es)
1 x EPU switch(es)


Aside from not knowing the majority of the jargon used in this list, I am concerned that just because a connection fits in a certain spot, doesn't necessarily mean it SHOULD go there.  My primary concerns when looking at my motherboard were trying to figure out the USB 3.0 issues, and then any extraneous wiring of which I discovered a couple fans that were not connected. 


First off, I noticed there was a 3.0 USB 4 pin connector on the motherboard, which I had a fan connected to for some reason...  I removed that but couldn't find anything internal that seemed to come from any USB ports to connect there, but I suspect the front USBs should be connected here? There were no wires coming from the Front that looked like they would fit there.


Secondly, my chassis came with 2 x front-mounted 120mm, fans 1 x rear 120mm fan, 1 x 200mm side panel fan, and as far as I remember I stalled two additional fans on top.  Heat has not been an issue, but this list from my motherboard makes me think I would not be able to connect all the fans, however I think I was able to connect all the fans to something... although I did not confirm after the fact if they were all working.


I'm posting this for some clarification on "just because a connection fits in a certain spot, doesn't necessarily mean it SHOULD go there", the USB 3.0 pin connector, the fan situation, and more generally if there is any concern the way I have things connected could have my system running less efficiently/effectively than it should.


It's obviously an older system now so I assume the latter is not really a concern if I have survived this long...


Thanks for your time!

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#2 jjkusaf


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Posted 30 July 2018 - 10:53 AM

What? The USB 3.0 header is the long 20/19 pin connector (middle/front of the Mobo) ...it isn't a four pin.

Obviously, you shouldn't hook up things to ports for which they weren't intended.

Not sure what your question is otherwise?

#3 OldPhil



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Posted 30 July 2018 - 11:24 AM

Find the manual then re check your connections!

Honesty & Integrity Above All!

#4 blitzjg

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Posted 30 July 2018 - 12:56 PM

Fair point, I forgot I could look up the manual online!

#5 DavisMcCarn


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Posted 30 July 2018 - 02:31 PM

Here is your manual:


Pages 2-2 and 2-3 have a picture of your board showing the connectors and what they are for.  Your front panel USB ports ought to be plugged in to one of the USB headers labeled 15 in the picture. and the chassis fans should go to the headers labeled number 1 (one).

Computer dinosaur, servicing PC's since 1976

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