2009-2012 - Tapping 4 Pin power at front of case

Discussion in 'Mac Pro' started by handheldgames, Apr 5, 2013.

  1. macrumors 6502a

    handheldgames

    Joined:
    Apr 4, 2009
    #1
    Like many MacPro users, I need additional power inside my PCIe/Drive bay for additional components, such as PCIe USB3.0 cards, etc.

    While I already tapped the power in the DVD bay, I would rather tap the power at the source: a 4Pin mini molex jr female motherboard header, located at the front of the MacPro case, by the 2 DVD power headers.

    Ideally, we need a 4-Pin Mini Molex Jr cable with male/female connectors to tap into the power with an additional 4-Pin female molex tap that can be extended as needed inside the case. I have searched and can only find the components, not an assembled cable.

    Has anyone else gone this route? Would be interesting to hear your solution. I'll be ordering the kits tomorrow to hand build a couple sets.

    [​IMG] [​IMG]


    Thx,
    HHG
     
  2. macrumors 68000

    Joined:
    Sep 12, 2007
    #2
    Where are these headers? I've never seen them!!

    Got a photo?
     
  3. thread starter macrumors 6502a

    handheldgames

    Joined:
    Apr 4, 2009
    #3
    Pictures are an excellent idea. Ill snap some pics when I get home from work. The power header sits near the upper left corner of the motherboard to the left of the PCIe bay fan. I found it when I was looking for a power source for two fresco logic based USB 3.0 connectors.

    The fan can be easy unscrewed and pulled out to reveal the connectors. It's power connector is integrated into the housing making reinstallation a snap. The only gotcha is aligning the PCIe release bar, which is super easy.

    Tapping the power at that location makes more sense than plugging and routing a power cable from the optical bay.
     
  4. macrumors member

    Joined:
    Dec 23, 2009
    Location:
    SW, UK
    #4
    Okay without pulling my set-up apart to have a look, I have a gnawing feeling this is the Fan unit power, how can you tap it without surgery to fan connector?

    Maybe the photo's will help.
     
  5. macrumors 601

    ActionableMango

    Joined:
    Sep 21, 2010
    #5
    Edit:
    Wait, I'm confused. Your text talks of mini-molex to molex, but your picture shows a black PCIe power connector.

    I thought the PCIe power pin are all 12V. Molex 4-pin has 12V and 5V. If you are talking about using the PCIe power ports to power molex devices, you should make sure those molex devices do not need the 5V line.
     
  6. macrumors 68040

    666sheep

    Joined:
    Dec 7, 2009
    Location:
    Poland
    #6
    OP means this one, I think:

    [​IMG]

    AM: connectors on pic aren't PCIe.
     
  7. thread starter macrumors 6502a

    handheldgames

    Joined:
    Apr 4, 2009
    #7
    PCIe connectors on the MP motherboard are MiniFit Jr dual row 6 pin connectors. (between SATA and Mini Molex 4 Pin connector for the PSU Fan) The power connector for the Optical Bay is MiniFit Jr dual row 4 pin and it's in a great place to grab an additional power line.
     
  8. macrumors 601

    ActionableMango

    Joined:
    Sep 21, 2010
    #8
    I obviously had a huge brain failure. :(

    It does seem like a good place to tap into power.
     
  9. macrumors regular

    Joined:
    Sep 13, 2012
    Location:
    London
    #9
    Did you ever get these working? I have a USB3 card I'd like to add some power to.
     
  10. macrumors 601

    Tesselator

    Joined:
    Jan 9, 2008
    Location:
    Japan
    #10
    Why do you good folks seem always to want to misuse your machines?
     
  11. thread starter macrumors 6502a

    handheldgames

    Joined:
    Apr 4, 2009
    #11
    More of a repurpose than a misuse. Optical drives followed the path of the floppy years ago ago. I've been too busy with work to build one. I have a power cord that's snaked through the bowels of my the DVD bay for now, just needs to be replaced sometime eventually..

     
  12. macrumors 601

    Tesselator

    Joined:
    Jan 9, 2008
    Location:
    Japan
    #12
    k, just don't forget and hook up a USB 3 device (or two) that draws more than that connector can supply. :p
     
  13. macrumors member

    Joined:
    Jan 30, 2008
    Location:
    Sacramento, CA
    #13
    I also recently ran power from the optical bay to supply to the Orico 4-port USB 3.0 PCIe card. This thread interested me, so I started looking into it myself.

    It turns out that the connectors used on the motherboard for ODD power aren't Molex Mini-Fit Jr., but rather Micro-Fit 3.0 connectors. They are just a little bit smaller, and also have a slightly different configuration on the way the square "pins" are angled on their corners.

    The link to the connector used is here.

    I couldn't find a kit with all the components in a neat package, so had to order the male/female connectors and male/female pins separately, along with the crimping tool.

    This just seems like a better solution, with less wire required. I just ordered the parts, so it will be a while before I try and build the cable assembly.

    Mark
     

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