Making a PSU Power Cable for a Micro ATX MB to Fit Into a Normal Size PSU

Introduction: Making a PSU Power Cable for a Micro ATX MB to Fit Into a Normal Size PSU

About: I just like to make stuff.

I got this Micro ATX dell Pc with a blown up PSU in it off the curb,  I had no idea if it worked or not, After hooking it up I found that it did not power up, So i had a hunch the PSU was shot as it smelled burnt.

 A closer inspection revealed that it was in fact a 24 Pin connection but was allot smaller then my reg 24 Pin PSU. And the cost of new PSU for this Dell was well over $100.00 to replace. And I wanted to see if this was a working PC another hunch it was a good PC just a bad PSU.

So I had to act and came up with this solution to my problem, And anyone who can solder wires can do this, It was very easy and I needed to do no research on the web to accomplish this task.

Power tools such as Drill's and Saw's can easily hurt you, If you could ask my Ex friend Ray about the time I used him for a Vise, He would tell you that it sucked and DON'T DO THAT. Soldering Irons can cause severe burns and fires, use in a dry area keep any and all flammable liquids away from your work area, And always keep a fire extinguisher close by do not breath in vapors from flux or solder. Use proper care when using your Iron. I am not responsible for any damages to you or your PC ,man or woman cave, bat mobile , motor home, boat, flying saucer, jet aircraft or any other thing you may or may not own should you go forward and do this. As I know about enough to be dangerous.

Tools and parts that you will need:

Soldering Iron.
Solder.  (I use 60/40 rosin core Electrical solder)
Pair of wire strippers / cutters.
Helping hands or other suitable device you may have to hold our parts to be soldered.
Heat shrink tubing or black Electrical tape. (Heat shrink would be best)
Old junk 20 Pin  Motherboard with the extra 4 Pin connector (Female)
24 Pin Male connector from Micro ATX. ( I salvaged mine off the junk OEM PSU)
Junk Normal size PSU for the longer leads to extend the length of this connector.

Step 1: Getting a Good Look

As you can see here in Photo #1 the size difference between the Micro ATX connector and normal ATX connector. This female connector is only 20 Pin, I must have the other 4 pin female connector to make up out 24 pins.

Photo #2   You will notice if you count the pins on Female connector on the motherboard it has all 24 pins and the salvaged connector does not.

Photo #3  Is simply the 4 Pin Female connector use your Dremel to cut this off the Motherboard, I would suggest leaving a little extra around the edges to give a little more room to work with.

Photo #4  Same goes here as in Photo #3,  Remove 20 Pin Female connector from Motherboard.  Pliers were used in the removal of the Female connectors from junk Motherboard along with dremel.

Step 2: Wire Stripping and Tinning

Now for reasons not controlled by me, The Male connector only had  very short  length  of wire, from PSU to connector was around 5 inch's So I felt the need to make some longer leads to the Male connector.

Start by stripping about 1/2 inch of insulation from each wire on the male connector.
Cut a nice length wires from the junk Normal size PSU, There are a few different ways to solder wires together I prefer to try and keep the nice and flat straight  makes for a much nicer job well done when completed.
Apply flux to wires and solder. Helping hands is your best friend at this point as you need to do this 24 times 1 for each wire Fun Fun :) should you choose to extend the length as I am doing here.

RED wires = 5 volts
YELLOW wires = 12 volts
ORANGE wires = 3.3 volts
BLACK common / Ground
BLUE - 12 volts
Green power stand by

Step 3: Connecting the Female Connector

Looks scary huh?...  Not to worry its not that hard, You just have to make sure that your solder welds are rock solid.

Start by stripping about 1/8 inch of insulation off all 24 wires and tin them,  Also at this point I would suggest putting the heat Shrink on all wires before you weld them. I would also advise if your using Electrical Tape, Tape each wire up after welding 1 by 1.

Take the Normal PSU and plug it into the Female connector and match up the wires for the 20 pin end for end, you will have 4 wires left over for the 4 pin Female connector repeat and plug the 4 pin together and match up the wires and solder.

I can't stress the point enough for making sure your welds are solid. Should your welds fail your pc could crash, fry, stop working.  So be sure your welds are rock solid and wires all match up red for red +5 volts,  yellow for yellow +12 volts, orange for orange +3.3 volts, black for black common/ground, Blue for blue -12 volts, green for green power stand by.

Time for the Heatshrink or Electrical tape on all welds, Take your time an do it well, if your using Electrical tape keep tension on the tape as you wrap the weld less mess and less likely to unwrap.

Step 4: Plug It in and Power It Up!

Plug it and hit the button!

If all goes as planned your PC should fire up just as mine did, no explosions or cooking sounds or bad smells arose.
Not bad for free junk that was tossed out to the curb. 

Only thing I had to do was install a fresh copy of window's 7 ultimate 64 bit 10k RPM Raptop sata HD toss in my nice 9500Gt PCIE express 4GB Corsair Duel channel RAM and this thing hauls arse!  On a further note I did not have put all my hardware on this motherboard but I did cuz I can. >:)

Sinister grin  and the mad scientist laugh MUHAHAHA MUHAHAHA MUHAHAHA! >:)

Hope you all found this be helpful and insightful.

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    3 Discussions


    7 years ago on Introduction

    Should mention that that's a proprietary board (Dell is famous for it), not micro ATX.
    Micro ATX boards use the standard atx v2.3 connector.
    But anyway, good Ible.


    Reply 7 years ago on Introduction

    Well from what I have seen so far all the Micro ATX boards are using a 24 pin power connector. This may be a Form Factor: Mini-ITX.


    Reply 7 years ago on Introduction

    Yes, a 24-pin ATX connector
    But it's the same pitch as the 20pin ATX connector.
    What is on your board is not ATX.