A friend of mine asked me take a look at his power supply, because suddenly it stopped working. Of course I said yes, and the first thing to check after I removed it’s top, was the fuse. The fuse was wrapped inside heat shrinking tube which made the checking a bit difficult. After peeling some of the shrinking tube I was able to measure it’s continuity and find out that it was blown. At that time I hoped this was the only problem, I replaced it and powered the supply, but my joy was short, because the new fuse was blown too.
Obviously the problem needed further investigation, so I went along and checked the rectifier bridge, which was ok. The capacitors looked ok, so the next thing I had to check was the two switching transistors. To do that I had to remove the hole radiator which contained more than the transistors. Checking the transistors gave me the answer to the problem, because I found both to be broken. But now a new problem was raised when trying to find replacements for the two transistors 2SC3320. I was only able to find these in stores across US and China and both of these places would make the shipping and tax costs to high to be worth buying from there.
Now I have only two options, one is for someone to have a broken power source that has these same transistors, and that they’re still working, and the other is to find a replacement for these transistors, which I tried but with no luck. I wasn’t able to find another transistor to match it’s characteristics.
This is the datasheet of the 2SC3320 transistor. If you have any ideas on how I could solve this, please comment.
This is a very simple to build and very powerful power supply for basic electronics, but for a newbie can seem confusing if he tries to make the conversion on its own. The power supplies used in PC’s have useful output voltages like 5V, 12V, 3.3V and even some negative outputs -5,-12V. While the positive outputs can handle significant current, the negative rails tolerate just a few hundred milliamps.
I recently needed about 12 and 10A, since my bench supply can handle only 2A I used an old 250W PC source, on the label was 12V/15A but the voltage dropped to 10V at 5A load, so don’t be surprised if you encounter similar “effects”.
Don’t forget the dummy load on the 5V rail, to be honest I never used it and the supply worked just fine, but to avoid any problems load the output with 0.5A. In lack of power resistor use any 12V light bulb, it will do just fine.
ATX power to bench power: [link]
tizz78 the author of this project writes : The purpose of me attempting this mod was simple : I have 4 xbox 360’s and 2 360 PSU’s . As anyone can ” do the math ” you can see why I did it and especially looking at the price of 360 PSU’s . I had this old one sitting around so I figured I’d go for it .For this mod I used an older AT 250 watt power supply that already had a switch to turn it on and off . If you use an ATX power supply you’ll have to connect two wires together to keep it in ” standby ” or ” always on ”
Xbox 360 powered by an ATX power supply: [Via] – [Link]
Have you ever tried to power up an atx power supply ? if yes, you’ve noticed that there isn’t any obvious way to do it. I mean there is no On/Off switch that you can just flip and the power supply turns on. So you might think that you need a pc to power up an ATX power supply, well you don’t. By following this instructions you can power up any atx power supply because they all power up on the same principle.
In the first picture you can see the 20 pin atx plug, but don’t worry if you have one with 24 pin that works too. Now identify the green wire, notice in my picture you can clearly see the green wire.
Now next to the green wire it should be a black wire which is GND. All we need to do to power up the atx power supply is connect the green wire to the black one. You can see in this next picture that i used a piece of thick wire to connect the two. The piece of wire solution is just a temporary one to show you that this works, instead of the wire you can use a switch.
Make sure you don’t leave the power supply running without a load, because it will overheat and smoke will start to rise. You should be very careful while working with an atx power supply because there are high voltages and currents going trough that thing, and you don’t want to get yourself hurt. So don’t underestimate electricity, because it can kill you.