I installed 3 80mm fans recently and my computer has started clicking. Its occasional, like every hour or 2. The noise is similar to that when you first boot up your computer. It lasts for a second and then goes away. Some say it could be the gpu's fan, but its a mx 400 with no fan. I hope its not the hard drive or the psu. Btw i have 2 plextor dvd+r drives, 2 hard drives, and an amd 1700+. The psu is antec true power 420watt. What could it be??? Can it be that im stressing out my psu?