TechSpot

Tutorial: How to build a Dual psu system using 1 Power on button

By SOcRatEs
Jul 7, 2006
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  1. Dual PSU rig, using 1 Power on button

    Setting up your system to run dual (Master/Slave) psu's is very simple.
    What you need:
    2 atx psu's (example: Matched 300w), electrical tape,
    2 wire connectors and space in your case.

    I chose to mount the slave PSU inside of case running
    Link wire 14(green) & 15(black) inside to pair up with internal PSU 20 pin.

    1. First thing to do is make sure that both psu's work.

    2. Now locate the plugs that hook up to the motherboard on both psu's. (20 pin)

    http://i42.photobucket.com/albums/e302/SOcRatEs120/My Rig/20pin.jpg

    3. Identify Link wire 14(green) & 15(black) on both PSU's.
    Cut the 20 pin plug off the slave psu. Now cut and cap (elec. tape)
    remaining 20 pin wires (not the molex wires) all the way back to the slave PSU.

    4.Then splicing wire 14(green) & 15(black)
    to the master PSU wire 14(green) & 15(black).
    note: Do Not cut plug off the master PSU

    5. I cut only wire 14 & 15 on the master PSU about 1 1/2" from plug
    and used wire connectors to make the following connections.

    6. Link wire 15 (black) on both psu's together, line 15 is ground and to run
    dual psu's you need a common ground.

    http://i42.photobucket.com/albums/e302/SOcRatEs120/My Rig/casemodp3_6.jpg

    7.Link wire 14 (green) on both psu's together, line 14 is the "ps-on" line
    which turns the psu's on using just the Power on button of front of case.
    Now your done with the master psu, the master psu is the supply that
    mounts in your standard PSU spot and plugs into the motherboard.

    I have used dedicated molex's from the master PSU to run my 6800 gt
    and motherboard (20pin & 4pin Pentium) & HDD'S/ the slave PSU for
    cdrw & dvdrw, internal fans & external radiator 120mm fan & cooling pump.

    Note: this method only allows you to run two psu's in one case as separate
    units, master/slave. The master PSU will supply the 4 pin plug to the
    motherboard. I have since cut all un-used cables from the slave PSU ie;
    20 pin & 4pin, mine had a weird 5 pin too.

    http://i42.photobucket.com/albums/e302/SOcRatEs120/My Rig/SideFull.jpg
  2. TimeParadoX

    TimeParadoX Newcomer, in training Posts: 2,438

    Really nice guide, I might use this in a build that needs like 1400w ( 2 700w PSUs ) for a DX10 build :)
  3. Ph30nIX

    Ph30nIX Newcomer, in training Posts: 359

    I think that 5pin may be a SATA one (has extra orange wire??. I had one that fit straight into my sata2 drive, but it didnt actually do anything. I have used a second psu but never wired it to the one switch, great guide!!
  4. MetalX

    MetalX TechSpot Chancellor Posts: 1,909

    I'm pretty sure it's an AUX line. Some old motherboards used them in addition to the 20 pin connection, kind of like the 4 pin that new motherboards use.
  5. Powerpc

    Powerpc Newcomer, in training

    Dual PSU

    http://www.techspot.com/vb/topic53694.html
    i used this info with no problems but one and i fixed it very simply my only problem was the suggestion of cutting the wires back to the outside of the power supply thus makeing it look like hell in my case i had to replace the cooling fan on the Slave PSU so while i was in there i cut the wires back to the inside of the PSU and capped them with heatshrink if you don't know what you are doing i don't suggest that you open up any PSU!!!
  6. SOcRatEs

    SOcRatEs TechSpot Paladin Topic Starter Posts: 1,382

    That is a very good suggestion on both points!
    Mine are outside the psu & tapped individually.
    They make clamp style caps that work very too..

    I'm glad this help you!
    How do you like your system now?
    Have you noticed any difference?
  7. Powerpc

    Powerpc Newcomer, in training

    Just Finished DUAL PSU Hookup

    I just got it done and yes i have noticed a difference computer nolonger rebooting on startup lights in house dim alittle more but what the hell i have more than enough power now and the added ability to add 6 more hard drives THANK YOU! THANK YOU! THANK YOU!
  8. CMH

    CMH TechSpot Chancellor Posts: 2,573   +9

    Lawl, powering your comp causes lights to dim in your house? :D:D:D

    I sincerely hope you're joking, cause the only reason that could happen is if your house runs off a generator in the backyard or something!!

    Reminds me of a joke I once read, something about tech support and a guy's comp restarting every time someone used the toilet :D (house was on generator supply, and toilet pump causes power dip).
  9. twite

    twite TechSpot Paladin Posts: 1,083

    Lol..this happens to me when i turn on a lot of things. My house was built in the 50's, and is still using the original wiring.

    When you turn on the cooler, computer, hair dryer(sister), fan, or my speaker system, my lights dim.

    I have also gone through probably 20 fuses from my mom/sister using hair dryers at the same time.
  10. CMH

    CMH TechSpot Chancellor Posts: 2,573   +9

    wow... you're not kidding!

    Time for an upgrade.... for the house I mean!


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