I just bought a 400W CyberZone Psu and saw something interesting when I opened it. Aside from the rediculously long cables, there was one cable that plugs into the 3pin plugs located on the motherboard. Normally I thought that these plugs supplied power, so I am uncertain wether or not I should plug it in.
Its a two fan PSU. Both fans are running. I cant figure out what its for.