Question, that has been asked before...

[95BlackGA 5,000+ posts]

I know this has been asked before, and I've searched this forum, and used google, can't find it anywhere. I was wanting to know exactly how to turn a computer power supply into a 12v supply for testing head units. I have SEVERAL laying around, but can't figure out how to turn on, and not burn up. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

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[trunks9_us 10+ year member]

your plug it into the amp //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

bump for the guy i wanna know to.

 

[WulfComp 10+ year member]

well, to turn on the PSW you need to jump the (most of the time)-green wire with a black if you look at the ATX plug, with the clip facing you and wires up it should be the 4th wire from the left. again should be green, but have seen it other colors. Black is your neg. Yellow is your +12v red is your +5v That should do it, just make sure your fans are working. Good luck

 

[Immacomputer 10+ year member]

It's really simple, especially if you're just trying to power on headunits. It honestly takes pretty much no modding at all.

First, take a good look at the power supply and familiarize yourself with the wires coming from it. The two sets that are of interest are the 4 corded molex cables. These have two black wires, a rid wire, and a yellow wire. All you need to be concerned about is the yellow and the black wire (either one or both). This is your +12v and ground.

Here is a picture of what I'm talking about:

http://www.viaarena.com/images/articles/pctipsrom%20040.jpg

Next, notice the main bus line. This is the big cable mass that ends in a large plastic piece that connects to the motherboard. Somewhere in this mass of wires, you will need to locate a green wire and a black wire. Take a paper clip or even a staple and short the green cable to ground. I use a staple to short mine and it works fine and keeps the power supply usable in case I need it for a PC.

The red circled cable is the one I'm talking about and the blue line is showing you HOW to short not WHERE to short. I can't see a green cable in this picture so I just drew it at random.

Once you do that, the power supply will turn on when you flip the switch and have it plugged in.

To hook up a CD player, hook up the Yellow cable from the power supply to the red and yellow cables from the headunit wiring harness. Then hook the two grounds up and the headunit will turn on when the power supply turns on.

To connect the headunit, I recommend using a 4-pin molex adapter so that you don't have to splice any wires from the power supply.

Something like this:

http://www.silverpcs.com/images/cables_18_ysplitter.jpg

Wulf was faster, I was more in depth. He wins.

 

[WulfComp 10+ year member]

hold on, fixing the picture from above.......

Ok, there is the green wire, and the black. should be simple.

 

[Immacomputer 10+ year member]

I win round 2.

 

[WulfComp 10+ year member]

your sword is strong and swift my friend......some day I will have my vengance

 

[95BlackGA 5,000+ posts]

Thanks. When I do this, shouldn't the fan start? All I hear is a slight ticking...

 

[Immacomputer 10+ year member]

If you just short out the main bus line and have no load connected, the fan should start. What PSU are you using and how old or how used is it? I have 3 that this has all worked on and they range from 3 years to 10 years old.

 

[95BlackGA 5,000+ posts]

It's probably about 6 years old, came out of my old eMachines tower.

 

[WulfComp 10+ year member]

If you have another one I would suggest using it. I have to replace more power supplies in Emachines than any other computer, bad part is, when they go, alot of times, they will take the motherboard with them. Those bestec power supplies aren't worth crap.

 

[spoonraker 10+ year member]

I have a power supply out of a 1998 Compaq that still works fine, I use it for general screwing around with DC devices indoors //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Oh and like others have said it's really simple. Just find a 12v power and ground cable in one of the 4-pin connectors and cut the end off. Split the 12v+ to use for both power and remote wires, then just jump two of the pins on the ATX cable to start up the PSU.

 

[oldschool4me 10+ year member]

works good for a head unit. not good for amps, it cooks the supplies.

 

[Immacomputer 10+ year member]

Depending on the amp and supply, you can squeeze a few hundred watts out of it. I had a 300wrms kenwood amp hooked up on my Antec 350 and no problems at all from the supply or amp. I was able to drive the sub to the same excursion levels in my house as well in my car (both amp and sub).