If your computer ever stop working suddently and stopped powering up, this is one way to test your Power Supply Unit (PSU) to find out if it blew up...
To find out more information about this PSU test using a paper clip please visit this link: http://aphnetworks.com/lounge/turn_on... (I'm not affiliated with this website, it's just a link that I found useful when troubleshooting my PSU issue)
My PowerCool 500w (just over a year old) stopped working a few weeks ago and had to replaced it, so I got the iCute 500w instead, (here is a link to the website where I bought it from http://www.maplin.co.uk/icute-titaniu...), which seems pretty good so far, I love the way the cable can be plugged individually and it seems quiter than my previous PSU.
In the video you can see that once connected the PSU fan only spinned for a couple of seconds, which means that it is dead... if it was in working order it would have just kept on spinning until switched off.
Disclaimer: Posted 'AS IS' and test at your own risk.