Well about a week ago I finally finshed my Xbox 360 ATX PSU conversion.
With this mod the wires barely get warm to the touch.
It took a bit longer then expected waiting for parts was the real time killer.
What makes this mod a bit different then what I've seen here is its FULLY REVERSIBLE.
In other words the ATX PSU can be removed at any time and used on a computer if I ever have the need.
Or if the PSU ever fails it can easily be disconnected from the cable and a new one reconnected WITHOUT touching a soldering iron.
The PSU is an Antec SmartPower 500 Watt supply this supply model has bad capacitors in it so a recap was in order I used Panasonic FCs. After the recap they are rock solid.
This PSU has 17 amps on 12V rail 1 and 19 amps on 12V rail 2.http://i15.photobucket.com/albums/a391/krankshaft/PSU.jpg
No sissy Micro ATX supply to burn up here
Now onto the things you will need:Talismoon PSU Energyzer (For 360 Power Plug)
24 Pin ATX Power Supply (With at least 16.5 amps on the 12 volt rail)
24 Pin ATX Power Supply Extension cable (It has a male ATX connector on one end and a female on the other)
You won't find these at your local computer store you will have to Google it and order one. It is very important that its a 24 pin EXTENSION cable and NOT a 20 pin extension cable or 24 to 20 pin CONVERTER cable.
Dremel Rotary Tool With Bit or Thin File (To Fit into female atx connector)
Small NPN transistor like the 2N4401 found at Radioshack. (This is so the PSU turns on and off with the 360)
10K ohm 1/2 watt resistor (This protects the base of the switching transistor from getting destroyed)
Continuity tester or multimeter
Heatshrink tubing or electrical tape
Wire strippersPrepping The Energyzer Cable:
First things first DO NOT
use the Energyzer cable in its stock fashion. It pulls all 16.5 amps off 1 WIRE of the 12 volt rail this is a safety hazard. Forum members have reported overheating and even melting of the ATX connector because of this.
That being said the first step is to clip off the ATX connector on the Energyzer. Once that is done carefully strip off the gray insulation. You will then see braided wire this is shielding pull it away and twist it together nicely.
Under that braid you will see black insulation (CAREFULLY) strip this off and you will be greeted with a series of wires. 4 yellow 4 black 1 red and 1 blue wire and of course the twisted braid wire.
The yellow wires are for the 12 volt rail, the black are for ground, the red wire is for the 5 volt standby, and the blue wire is the PS Enable wire.
Strip the insulation off of each of these wires and twist them. Then tin them with solder.Finding the connection on the 4th wire:
Now there are four 12 volt and ground wires. While there are only three 12 volt and ground outputs on the 360 power connector. The reason for this is because the smallest 12 volt and ground wire are connected together at the 360 connector.
The first step is to isolate which wires are connected to each other the simplest way to do this is to use a continuity tester or a multimeter set to ohms. Touch your probe on the small yellow 12 volt wire then touch your other probe to one of the other three 12 volt wires. Once you've found which wire its connected to twist them together and solder them together. Do the same for the black ground wires.Prepping the ATX extension cable:
Now you should have three 12 volt wires, three ground wires, one red standby wire, and a blue PS Enable wire. Its time to make this cable get out your ATX 24 pin extension cable. Clip all of the wires at the halfway point and take the side with the female ATX connector.
Now there are alot of wires on this ATX connector that we don't need. I am referring to the ATX extension cable you just cut and NOT the PSU ATX CONNECTOR.
You will want to remove ALL the wires you will not need from this connector. To do this you will need a small flathead screwdriver. Now look into the ATX connector and press the blade of the screwdriver firmly into the holes on each side of the metal connector. Check out the picture to see the areas to push the screwdriver in.http://i15.photobucket.com/albums/a391/kra...Screwdriver.jpg
Once you depress the screwdriver on both sides pull the wire and its crimped connector out.
Now the object here is to remove the wires to make your ATX connector look like this.http://i15.photobucket.com/albums/a391/kra...ft/LikeThis.jpg
That leaves a purple 5 V standby wire, 5 ground wires, the green PS ON wire, and 3 12 volt wires. Please note that the black and red wires to the left are the other 2 12 volt wires. I know that they are not yellow but that is what they will be for.
Now we need to do a little modification to the ATX connector to make everything fit. First remove the extra 4 pins from the ATX connector on your power supply they should either pull off or slide off. We will be using the 12 volt connector shown next to the ATX connector and NOT the standard 4 pin connector.http://i15.photobucket.com/albums/a391/kra...onnectorUse.jpg
Now connect the connector into the female ATX connector. Don't worry you can't put the connector in the wrong way or in the wrong place.http://i15.photobucket.com/albums/a391/kra...inConnected.jpgMaking the 12 volt connector fit:
You will notice there are 4 more pins with 2 wires on them. We will need to make the ATX 12 volt wire fit here. In order to do this we will need either a Dremel tool or a thin file. Look into the ATX connector you will see two square holes and two holes that are not square. You will need to file these pitches off with either a Dremel or a file and make them somewhat square. Until the 12 volt connector fits. You want to remove just enough so that there will be a tight fit so that the connector doesn't slip out.http://i15.photobucket.com/albums/a391/kra...nectorFiled.jpg
Please note you WILL be able to put this 4 pin 12 volt connector in the wrong way. Make sure that the 2 yellow wires on this connector are FACING the black and red wires.http://i15.photobucket.com/albums/a391/kra...inConnected.jpg
If you install this the other way around the 360 will work however all of the 12 volts will be pulled out of 1 wire on the ATX connector. This is the very reason why we had to chop the end off of the Energyzer cable in the first place.Putting it all together:
Now that we know everything fits disconnect the PSU from the female ATX connector and lets get started.
Now we're ready to solder the ATX connector to the PSU Energyzer. Be sure to either insulate the soldered joints with electrical tape or heat shrink tubing. I used heatshrink tubing for a neater look but electrical tape works just as well.
Solder the the first yellow wire to a yellow wire on the Energyzer. Now solder the other two wires (Red and Black) to the left and to the bottom of the first 12 volt yellow wire to their respective yellow wires on the Energyzer as well.
Now solder the three black ground wires on the Energyzer to three of the black ground wires on the connector. Also solder the braided sheathing to its own ground wire.
Solder the purple 5 volt standby wire on the ATX connector to the red wire on the Energyzer.
Now we are left with a blue wire on the Energyzer and a ground wire and a green wire on the ATX connector.
Here is where the transistor and resistor come in.
A special thanks to the guys at the Scene who came up with this simple solution.
This simple circuit using a NPN 2N4401 transistor allows the PSU to only come on when you hit the On switch on the 360. Solder one end of the 10K ohm resistor to the base of the transistor solder the blue wire from the Energyzer to the other end of the resistor. Solder the Green wire from the ATX connector to the collector of the transistor and solder the emitter to the black ground wire on the ATX connector.
Please note if you bought your transistor from Radioshack the pinouts of the transistor are on the back of the package. If you have not consult the datasheet.
Now heatshrink or electrical tape all of the exposed soldered connections including the transistor leads properly. Please note if you use heatshrink tubing it must be slipped onto the wires BEFORE soldering
Now be sure to secure the transistor to the wires with either zip ties or electrical tape. The leads on the end of the transistor are fragile so don't bend them around alot or they could snap off. I secured my transistor like this.http://i15.photobucket.com/albums/a391/kra...dTransistor.jpg
That pretty much does it connect the 20 pin wire to the ATX connector on the Energyzer and connect the 12 volt 4 pin wire to the Energyzer as well making sure that the 12 volt yellow wires are connected.
An easy way to make sure you do this right is to make sure that the securing clip on the 12 volt connector is in the same direction as the 20 pin ATX connector.http://i15.photobucket.com/albums/a391/kra...inConnected.jpg
Power up your 360 and enjoy your cool running 360 power supply
.This post has been edited by AdamWest: Feb 26 2008, 04:36 AM