Introduction: Modified "Brick" Power Supply

Picture of Modified "Brick" Power Supply

I always appreciated Microsoft products quality, my Xbox360 worked pretty well for 5 years, despite the red leds of death fame, and it continues to do its work. This is the reason why I bought its "brick" PSU at a a fleas market, for about 12$. I decided to build from it a 12V power supply unit for my laboratory.
I've to thank some instructables members (dog digger and Skater_j10) for the help their ibles gave me to understand the connections.
Please if you're not familiar with electronics, inform about danger of electricity on some trustworthy sources (a simple but comprehensive one could be

Step 1: The Original Brick

Picture of The Original Brick

Let's see what I've learned and practiced.
My brick is the third generation model, because is less powerful than the first two, but it's even so very powerful. Indeed you can read from the back side data that it generates 12V DC at 150W, It also gives a secondary 5V 1A line, which is a very pleasant peculiarity.
The 5V line is always on, since it's the standby power source of the console, but the main line is turned on with a small current flowing between two contacts of the plug.
Pay attention that the psu retains high current in his big capacitors for about 10 seconds after disconnection, and probably some current remains also for more time, so please be careful to not touch circuits with fingers!

Step 2: Disassembling

Picture of Disassembling

If you open the psu container (unscrew the four screws which are hidden beneath the rubber feet) you'll find some interesting details.
Pay a particular attention to remove the cover and to slide out the PCB, because you have to assemble it again.

Step 3: Read the Labels

Picture of Read the Labels

Each wire is well labeled, so you can easily fond the Power Enable wire (blue one), which has to be connected with a +3V line to turn the PSU on. As Skater_j10 tested you can also use a +5V voltage, so it's easy to insert a switch between BLUE and RED lines.

Step 4: Peek Under the Metal Skirt ;-)

Picture of Peek Under the Metal Skirt ;-)

You can solder the switch wires on the back side of the PCB, but I preferred to solder them on the upper side, although that space is not handy to reach. I made this decision because I didn't want to interfere with other tiny components, since as you can see the space is highly crowded!

Step 5: Choose a Switch

Picture of Choose a Switch

I have now to choose the best switch to use and where to put them. I like both but then I had to choose the lever one because it occupies a smaller place. You can also buy smaller switch, it will probably help you to make everything fit inside the box.

Step 6: Drill the Hole

Picture of Drill the Hole
There is not much choice about the place, especially if you want to respect the following points:
  1. the switch has to be on the front side of the "brick"
  2. you better have to put it vertical to facilitate the activation and the power suspention
  3. you don't want to remove any inside component, least of all the fan or one of the heat-sinks
  4. you don't want to ruin the edge of the two halves of the container, so it will be again well-sealed
  5. you have to be able to close the "brick" with switch in place
Said that, I managed to find a good place in front of the pcb between the transistor and the out-coming power cable.
With an hand-drill make a little hole in the showed position, then enlarge it with some bigger bit.
You also need to cut a piece of the plastic support which interfere with the switch body.

Step 7: Test

Picture of Test

Insert the switch in place, then try to assemble temporarily the pcb so to see if it fits well. As you see the switch push against the transistor, but it's not a terrible fact. If you're happy you can now solder the wires to switch and pcb.

Step 8: Solder

Picture of Solder

Remove a bit of the insulation plastic of the yellow and blue wires, to to reveal copper. Apply some soldering paste, and solder the new wires extremities. Then solder these wires to your switch. Since the bottom pin of the switch could touch the blue wire junction pay attention it's the Power Enable line. The center pin will so be connected to the +5V line.

Step 9: Close the Brick

Picture of Close the Brick

Screw on the switch a little nut so to define how much the switch should hang out.
Before locking the switch insert the PCB sliding it into the slots of the vertical plastic supports (the two remaining ones), pay attention to not push too hardy any inside component.
Switch is now ready to be fastened with another small nut. Tight it hardy so it will be well locked.
Close the brick and check the working of the switch. If everything works well (the light becomes green when switch is upper position), you can fasten the four back screws and put on the four rubber feet, since everything inside the box is done.

Step 10: Crack the Plug

Picture of Crack the Plug

It's time to modify the plug to transform it into two standard power connectors.
Plug is hard to open, so it will probably breaks, but you don't need it anymore, so don't feel sad ;-)
You can either cut the wire before the stabilizer cylinder, or leave it in place and try to remove the rubber reinforce, as I did.
You'll reveal four colored wires, which obviously correspond to the inner wires and lines we've seen in previous pictures. 

Step 11: ...solder the Cables

Picture of ...solder the Cables

Solder all the groups except the Power Enable wire so to have four contacts. Solder then the three extremities to a couple of bipolar cables, so that the ground line is connected with a pole of each cable, and the other poles are connected to +12V (for a cable) and to +5V (for the other cable). In other words: connect black and red lines to a cable, and black and yellow lines to the other one ;-)
Leave the blue wire alone.

Step 12: ...and the Plugs

Picture of ...and the Plugs

These are the two 2.1mm standard plugs, they're the same type used by Arduino and many other tools and gadgets.
Notice that usually the inner pin is the positive pole, and the outer surface is connected to the ground.
Thread the covers onto the cables (how many times did you forget to do that?), then solder the wires to the inner pins. Before screwing the covers put some glue on the threads, so to make a tighter connection.

Step 13: Label the Sources

Picture of Label the Sources

Since the outer surfaces of both plugs correspond to ground there is no risk to make any short-circuit. It remains the problem to distinguish the +12V line from the +5V one. I've thought to insert a label on the plug itself and then cover it with a transparent heat-shrinking tube, but I haven't a transparent tube of the right size, so I opted for another solution. I printed two labels to attack on the cables with an adhesive tape.
You can obviously use different plugs for the different sources, but since this plug type is so common I preferred this way.

Step 14: Flip the Switch Indefinitely!

Picture of Flip the Switch Indefinitely!

Your new PSU is now ready, and you can enjoy to power your project with both +5V (for the micro-controller) and a 150W +12V for anything very powerful!
The fact that +5V is always on is very handy because it let you setting up your controller without the risk to electroshock yourself, and you can turn on the main power source only at the time to start the actuator.


ValdasG2 (author)2017-04-10

Hi i use your tutorial and i have small problem . I want use psu for electrolysis to make hho but when i connect psu to plates its turning of after 5 sec

JamesA9 (author)ValdasG22017-05-13

Hi, your drawing too much current, try using a 750w pc PSU, that should be good

JulioM92 (author)2016-10-23

I know this is kind of old post, this is the first time i see it. why do you want to strip the yellow cable for. i don't get that. isn't it the between the red and blue where the switch goes

PiratesDieff (author)2014-12-28

Hi! Great tutorial. Do you know whether the voltage standby is always indicated on the backside data?

Actually I don't know, but if it's a "brick" for xbox360 I think that is not possible...

Big Ugly (author)andrea biffi2016-09-08

thanks for ur ible andrea. however on step 8 I get lost. I can't see where wires are being soldered and I'm completely new to electronics. I've got everything exactly as u did including switch and switch placement. am I soldering a wire from the blue line to the bottom of 3 prongs on the back of switch and then soldering another wire from the red wire where it touches the board back to the top or middle prong of the switch? I can't quite make out where those brown wires that you've soldered to the back of the switch go. thanks for your help.

It's not an xbox360 brick. I'm trying to find one. Anyway, thank you for your reply :)

you are welcome!

I can't understand what you mean... +5V is always on, and led is yellow, until you switch and led turns green, +12V and +5V are now both ON.

I mean, can an adapter have +5vsb but it is not written in the output data, just the 12v is indicated?

-max- (author)2015-02-02

I actually had the same idea when modding my old xbox supply, although I ended up having short one of the optocouplers to the +5V rail with a bodge resistor, since the supply would keep going into overcurrent or short-circuit fail safe mode, sometimes when there wasn't even anything connected!!! let alone the ZVS driver that demanded lots of inrush current! Although now I am worried the thing will burst into flames someday when the output is completely shorted and there is no output protection whatsoever. Oh well :)

slamslam102 made it! (author)2014-06-11

I had one of these bricks laying around and a mini PC without a power supply. Thanks for posting this.

le-Sid (author)2013-11-03

I like this idea. I've used those power supplies in various projects as they are quite powerful and easy/cheap to find (usually about 30$ at local ebgames/gamestop) For mine though I've used a molex connector as I use it sometimes to test hard drives or dvd drives.. Nice Job, very clean and well explained :)

andrea biffi (author)le-Sid2013-11-14

Yes, molex are great for 12V + 5V power connections.

crazypj (author)2013-10-29

Sorry for multiple posts, don't know what happened to internet connection, it kinda stopped then freaked out

crazypj (author)2013-10-29

small power 'brick' could be added to your micro drill press to power LED lights
Your giving me too many idea's LOL :)

crazypj (author)2013-10-29

small power 'brick' could be added to your micro drill press to power LED lights
Your giving me too many idea's LOL :)

muhammajunaid (author)2013-10-20

I like your i'ble, and would surely make such a unit. I also want to make a multiple USB device Charging unit. Is it possible to step down the twelve volt to 5 volt output on this device while keeping the amps as high as possible?


On a second though, PC psu are very powerful and also danger, and I wouldn't recommend to connect USB devices on them..

Gelfling6 (author)andrea biffi2013-10-23

Andrea, It's do-able, but I would suggest only the types with the 5V loaded already, and ONLY after turning the supply on, connecting the device needing the USB connection for charging afterwards. But I would still check the voltages with a volt meter 1st. I've done this on many projects, using a 350W ATX supply, powering or charging devices. (latest, using a Radio$hack adapter, plugged into one of the old drive power connectors, to charge a Palm Zire-3, and latest, recharged my Kodak M341 with same supply.. the +5V stays very stable.

probably you can use a cheaper PC psu for this purpose, since it already has a powerful 5V line... just my though :-|

bullzebub (author)2013-10-21

i like this one! 12A in a silent package... i need to get myself one of those!
personally i mostly use molex connectors nowadays for 5 and 12v since they are so easy to source from dead PSUs and addon fans and stuff :-) that way i dont need to be afraid to confuse 5 and 12 v line :-)

andrea biffi (author)bullzebub2013-10-22

Yep you're right, I've lot of them, that's a good solution for both 12 and 5 volt.

charlessenf-gm (author)2013-10-19

I have no idea what the original connector looks like. So I cannot be sure its not some sort of 'standard' connector for which a mate could be purchased eliminating the need for destroying the original connector. I realize the thought comes too late, but maybe the next guy . . .

Also, since the wires you connected the switch to inside the brick extend through the power cord you cut and soldered to your 'cables,' why not install that switch on your board instead?

And, then, install a switch on the AC side of the brick so you could leave it plugged it and switch the power from the mains when not using it?

Thanks, they're interesting issues.
The plug (you see it in step 10) is specific for Xbox360 (not all of them, see here for more details), so it's very difficult and useless find a proper female plug.
Since it's a laboratory psu, I have no board where to install the switch, it has to be universal.
There is no space to install the main switch in the "brick", I could cut the 220V cable, and insert it there, but I don't need it since I usually have main switches on my multi-plug adapters on the wall.

charlessenf-gm (author)2013-10-19

I realize that you may have a limited collection of wire, but I would suggest that carrying the color scheme (yellow and Blue) to the switch would have been even better. Maybe a bit 'anal' but the sort of practice that you might appreciate years from now if you have to 'go in' again.

charlessenf-gm (author)2013-10-19

He is modifying a power supply built specifically for an X-box so as to be able to use it as a multi-purpose power supply. I saw a title "Power Supply Modification
by andrea biffi" in the email from Instructables and figured out what he was doing from the git go (page one). He's done a good job.

I meant to reply to the post by "manicmonday" when I wrote:

He is modifying a power supply built specifically for an X-box so as to be able to use it as a multi-purpose power supply. I saw a title "Power Supply Modification by andrea biffi" in the email from Instructables and figured out what he was doing from the git go (page one). He's done a good job.

Wyle_E (author)2013-10-16

I might use a more robust connector for the 12V. I don't know if that little coax plug can be trusted with 12 amps. BTW, 12 volts isn't a shock hazard, so I'd worry more about accidental shorts. A supply designed to deliver 12 amps can be a small-scale spot welder before its overcurrent protection kicks in.

andrea biffi (author)Wyle_E2013-10-17

Current is the dangerous property, and perhaps 12A are not deadly, but they're pretty risky. A car battery is 12V 50A and it could kill you.

VOLTAGE is required to drive current. You are HIGHLY unlikely to have a resistance of 1Ohm, unless we dug electrodes into your body.

A car battery can deliver many HUNDREDs of amps, and will only kill you if someone drops it on your head.

I loved your comment about the only way a car battery will kill you is if someone drops it on your head.

I can not believe the number of people that I've talked to that think touching both terminals on a 12V car battery (with the car not running) will kill you. It's absolutely amazing. They've heard the part about how few amps is required to kill you and know (or assume) that because a car battery has 400, 500, 600, 700+ amps that you'll be killed instantly if you touch both terminals. They simply don't understand the relationship between Voltage and Amps and what is required.

I loved your comment about the only way a car battery will kill you is if someone drops it on your head.

Point of order: A car battery doesn't "HAVE" current. It MIGHT be able to DELIVER current, up to the limit imposed by its internal resistance though....Some car batteries can deliver well in excess of 1000A - it ruins them, and the spanner you dropped across the terminals though....

fullobs (author)steveastrouk2013-10-19

I am not sure you have convinced the guys that know "Current Kills so a bigger A number = bad" here but I applaud your effort and also enjoyed your note about the best way to kill with a car battery :).

my mistake: 50 Ah, not A

My rectified 45KV light bulb is just as dangerous as 120V at 1A (its input) likewise 1V at 120A is equally dangerous.

You are clearly not qualified to assess the data in the table. and wrong. You should go away and learn some basic facts before posting. Higher voltages are the HAZARD, high currents the CONSEQUENCE, and its the current which kills. If the path impedance is not low enough for the high voltage to force the current then there is no hazard.

No it isn't. That's completely wrong

hmlasko (author)steveastrouk2013-10-17

We have at least one great techie amongst us!

kyismaster (author)andrea biffi2013-10-17

A few milliamps of current going straight through the heart will kill you instantly.

A Mini-van battery may hold somewhere in the range of 700A, not 50 A, 50 A might be like a lawn mower or something small.

It takes one or less amps to kill you.

Yet taking that fact, you can probably touch a 220v pole thats 100A, and with one hand and use your feet as ground, but my god will it hurt.

going from left hand to right hand, you are as good as dead jack.

andrea biffi (author)Wyle_E2013-10-17

Now that you make me thinking about it, that plug is probably not suitable for so much current... I've to search something bigger.

The plug is fine for that amount of current. Go bigger if you want (I always like to over-engineer), but the way you have built it is safe. If you still feel uncomfortable or unsure, put the brick use, and feel the connector for temperature every 1/2 hour. If it gets too hot to hold, you need a bigger connector.

Good instructable by the way. Very clear, logical steps, and very good photos.

Thanks Marcos, as PSU for laboratory this will not power very high loads for long time, so after your advice I'll left it as it is.
But I'm arranging to build a similar psu for my battery hacksaw (with dead batteries), it needs about 7 A or a bit more. In that case I'll make a better plug.

Ryan Hebron (author)2013-10-19

good instructable and an interesting idea i will have to try this some time.

Ktululz (author)2013-10-17

At the end of the step 3, I think you mean "between blue and red lines" instead of "blue and yellow lines".
Otherwise, it's a good instructable, I think I'll start mine soon.

andrea biffi (author)Ktululz2013-10-18

Ouch! Bad bad bad mistake! Thanks very much I've fixed it!

manicmonday (author)andrea biffi2013-10-18

It is a good idea to tell right at the beginning of any text the basic idea of the text as a whole so that the reader can determine if they are interested or not.

This instructable does not follow that rule, so I have no idea what this is all about. I understand that there is some kind of a modification to the power supply of a xbox360 and some mention of a "Brick" that I don't understand. I might be interested in this, but didn't feel like reading a huge amount to figure that out.

Can you help me with that? Thanks

andrea biffi (author)manicmonday2013-10-18

this gaming console's psu is called "brick" referring to his geometric proportions. About the intro, I think that sentence in the third line is pretty exhaustive...
I hope to have been helpful.

andrea biffi (author)2013-10-18

I'm sorry it was't pretty clear, I corrected "source" into "supply" the third line of the instructable:
"I decided to build from it a 12V power supply for my laboratory."

Tin Man (author)2013-10-18

As the blue wire is redundant at both ends of the cable, would it be worth adding it in parallel with the yellows? This would give three 12V conductors rather than two, and help reduce the source impedance. The 5V is always handy for use as a USB phone-charger.

About This Instructable




Bio: I'm an Italian freelance structural engineer, graphic designer and photographer, and I'm teaching physics in Waldorf schools. I always investigate electronics, robotics and ... More »
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