View Full Version : Making a test power supply from a PSU

06-23-2007, 12:56 PM
I had an old 200W power supply from a ****ty Gateway machine lying around and as it's pretty much usless for most PC's (it doesn't even use a standard ATX mounting) I thought I'd turn it into a test PSU so I can check fans or just when I need either 12v or 5v power for something.

So here's the PSU as I started:


With it opened up you can see all the wires going to the circuit board. I don't need most of these.


So I trimmed it down to only the ground wires, the yellow 12v wires, the red 5v wires and the green wire I need to turn on the PSU.


Rather than use the original hole in the top where the wires came out before, I fed them through a small hole that was already in the end and then put heatshrink over the wires and fed it through the hole before shrinking it down. that will stop the wires from having any chance of wearing through and shorting.


I got a project box from the electronics shop to put all the wiring, plugs and power switch in.

First off the project box with the holes roughly cut out:


Then I attached the box to the end of the PSU with a couple of screws and started on the Soldering. I attached the plugs to the box with epoxy:


A couple of shots of the finished product. I added a car cigarette lighter socket, male and femae molex plugs, two 3 pin fan plugs and on the side I got a spring loaded speaker connection if I want to hook something up to 12v which doesn't have any sort of plug.


The power switch on the other side, which has the green wire from the 20 pin ATX MoBo plug attached and then going to ground through the switch. As this power supply had no power switch on the back I needed this to turn it on and off. If you have a PSU with a switch on the back you could just solder the gren wire to ground and use the switch on the back to turn it on and off.


And finally a shot of it happily running a fan from a 3 pin and from a molex:


Some black paint to finish it off:

http://img401.imageshack.us/img401/6643/cameradump160pv2.jpg (http://imageshack.us)

While digging through a box of goodies I found a cigarette lighter I got for free a while ago and thought it's power switch syle suited the PSU mod so I put it in.


I wanted to use a project box on the end rather than try and put all that in the PSU itself. Besides, plastic is a lot easier to cut with a dremel and file it to size.

So there you have it, a basically useless PSU turned into something I can actually make use of now and then.

Link to original thread (http://www.thebestcasescenario.com/forum/showthread.php?goto=newpost&t=9049)