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CPU fan runs, case fans don't.

I just finished my 1st DIY PC. The case fans (Coolermaster 922 HAF) won't run when connected to the motherboard (ASUS Z97-A). They do work if I connect them to the PSU directly.

I have a Crucial SSD, Seagate HDD, ASUS DVD drive and 8 (2x4GB) of Corsair Vengence RAM (1600 MHz) all connected to the MB properly (as far as I know). I do not have an operating system installed as I haven't gotten the computer to start properly yet. As far as I know, the computer should still boot.

Also, I don't have any kind of video. I'm using an eVGA Geforce 770 GTX OC connected to an LCD screen via DVI-D. The fans on it are running.

During "startup" there is no sound, no beep, no video. The fans turn on and the motherboard LED lights come on (showing it has power).

Any idea what's wrong? Motherboard? PSU? Operator/builder error?

Is it worth sticking a different (known good) PSU in it to see if anything changes? Do I have to plug all of the drives/video card and such in, or can I just use the main motherboard power cable to see if the BIOS screen shows up (or any kind of video signal)?
26 answers Last reply Best Answer
More about cpu fan runs case fans
  1. Best answer
    What PSU do you own?
  2. Oops. Didn't mean to click solved :(

    I am using an XFX 650 PRO
  3. You always want a quality supply running your build.
  4. That's a great power supply , and you should only have just the OS SSD attached while setting up the computer.
  5. Ok. I will keep that in mind and disconnect the HDD and DVD drive. However, the SSD doesn't have an OS on it yet as it is brand new. This couldn't possibly cause no video and the case fans to not run when connected to the motherboard rather than the PSU, could it?
  6. Did you have all the power plugged in even to the card?
  7. Card? You mean the 770? Yes. Both the PCI-E power connectors from the PSU are plugged in, and the fans are running on the ACX cooler the 770 comes with. The SSD is plugged in to the MB via a SATA cable and to the PSU via the power cable that fits the plug (lol). I didn't forget to put the RAM in either :(

    Edit: The motherboard has a long connector from the PSU plugged into it, with 2 rows of pins. As far as I know, that is the only MB power connector.
  8. You need to plug in the 8 pin CPU power from the supply.
  9. 0.0

    I'll brb.
  10. In Red

  11. Before I blow something up....Is it possible that power cable is split at the end into 2 4-pin connectors side-by-side? One of the connectors has a "C" on it.
  12. Yes like this:

  13. BRB grabbing something to eat.
  14. Grr...I immediately saw the plug on the MB you're talking about. Very clear now. The plugs from the PSU don't seem to fit though. Some of the pin cases (if that's what they are called) have rounded sides, and some are square. I'm rotating the plugs to find some way to match them up....don't give up on me!
  15. Ok, you can't really see it in the pic you posted of the MB, but the plug on the MB goes like this:

    (From left to right on the top row, as the pic you posted is oriented)

    Rounded, square, square, rounded

    (Form left to right on the bottom row, as the pic you posted is oriented)

    Square, rounded, rounded, square

    The only pair of 4 prong plugs I have don't match that. Well, one plug does and fits (as your photo is oriented) on the far left end, leaving 4 pins remaining. The other plug has 4 pins but they all have a rounded side to them!
  16. Connectors
    1 x Main connector (20+4Pin)
    1 x 4+4 Pin ATX12V / EPS12V CPU power should be labeled it probably is an 8 pin.
    7 x Peripheral
    8 x SATA
    1 x Floppy
    4 x PCI-E
  17. How do I post a picture from my phone on here? I use dropbox so it automatically shows up on my computer, but I don't know how to upload it like you are doing..
  18. You can tell which way it goes because of the latch on the 8 pin .
  19. I swear I don't have an 8-Pin connecter left. Just a 6 pin and those 2 4-pin ones. I will check one more time and make sure it isn't hidden behind a component when I installed it.
  20. 4+4 pin .
  21. OK. The only connectors I have that look even remotely close are the 2 4-pin ones that I've been trying and one of them just doesn't fit....2 6-pin connectors (obviously not right).....and 2 4+2 pin connectors marked PCI-E which are plugged into my video card (one 4 pin without the extra 2 attached to one plug, and one 4 pin with the extra 2 pin next to it for a total of 6 pins plugged in). GGAAAAAAAHHHHHHH!!!!!!!!!!!!

    Edit:

    Sorry, the PCI-E are 6+2 pins each, with only one of the plugs using the max of 8 pins)
  22. It's usually an 8 (4+4 ) pin you split it will say CPU on it.

    You don't need to spit it because your board is 8 pin.


  23. Hey! That's exactly the plug I'm talking about!!! I have that plug! See the 4-pin on the right in the photo? The one that has all rounded (on one side) pins? That #%%$@# won't plug in because 2 of them need to be square :-/

    Edit:

    The other plug (on the left) has opposing (diagonally) square and rounded pins. I need another one of those!
  24. Don't worry about the shape , the clip goes over the latch on the board , it can only fit one way.
  25. You, sir, are an effing genius. I....am not.

    And my computer boots.
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