Do you have an extra PSU lying around that is collecting dust and don't know what do to with it? You can use it as a test PSU! You can test your fans, cold cathodes, or mods and stuff whenever you want, without having to boot up your PC. Note: Most people will already know how to do this but I'm writing this for the newer people who don't know, so they also get the chance to do this. Also do this at your own responsibility, if anything goes wrong, I'm not responsible. Normally nothing should go wrong but still watch out, because you are messing with the PSU. BEFORE DOING THIS MOD, MAKE SURE THAT THE PSU IS NOT PLUGGED INTO THE WALL OR ON! Step 1 Find a paper clip or a wire, break it in half or cut it in half. Step 2 Bend it into a 'U' shape and insert it into the motherboard connector. Insert the paper clip ends into the same positions I did as shown in the pics. (Usually the top one (4 to the right) is a green wire and the 3rd one to the right is a black wire (ground wire) Step 3 Cover the motherboard connector with some tape for safety. Step 4 Plug in the cable on the back of your PSU. Flip the switch and that is all!