Here is a good trick for you tech-heads out there. Quite often it is necessary to test a power supply to see if it is working correctly and sometimes you may not have a spare computer to connect it up to. Fortunately there is a very easy trick to turning a power supply on with just a small piece of wire or paper clip.

If you are using a paper clip make sure you don’t touch it when you turn the PSU on at the wall otherwise you might hurt yourself or destroy components inside the power supply unit. On that note I take absolutely no responsibility for any damage done to yourself or your equipment if you do somehow manage to blow something up. I recommend that you use a small piece of insulated wire. This way all that you need to do is strip both ends of the wire bare so that you still have insulation in the middle of the wire where you can hold on to it.

That said the highest voltage rail on computer power supply is 12 volts so even if you do accidentally touch a live wire you are barely going to feel it unless there is something seriously wrong with it. You should always treat electrical devices like this with respect and do not take any unnecessary risks. Do not under any circumstances take the PSU casing apart unless you know what you are doing.

On all power supplies there is a big long plug that will either have 20 or 24 pins in it depending on the type of PSU. As far as I am aware the majority of these PSU’s use the same coloured wires in the same pin positions. Firstly turn the PSU off at the wall. Next you need to find the green wire (see the diagram below, it is labelled PS_ON#). It is pin number 16 on the 24 pin plug (Diagram Below Left) and pin number 14 on the 20 pin plug (Diagram Below Right).

On the 20/24 pin plug, poke your piece of wire into the pin on the green wire and poke the other end of your wire into one of the pins with a black wire coming out of it. There is one on either side of the green wire, use one of them, it doesn’t matter which one as they will both work.

With your wire in place, turn the power supply on at the wall and it should fire up and run as normal.