My Computer will not turn on or post!!

[Max-Powers]

My computer is in my sig. I have had it running for a couple months. It is my HTPC. I always leave it on, and reboot it every once in a while. It goes to sleep whenever it wants. Today I went to turn on my TV, the power lights for the computer were on so I knew it was not asleep, but I did not hear the fans. After turning it off and on I realized nothing was happening. I took the cover off and noticed only the hard drive will rev up when I start the computer. None of the fans, no CPU fan, case fans, GPU fan, nothing turns on. No picture.
I run Win7 32 and keep up with the latest virus scan. What could be wrong?! how do I fix this thing? It looks like everything is plugged in and I never move it. It has always worked before.

This is my power supply. Corsair CMPSU 650TX http://www.newegg.com/Product/Product.aspx?Item=N82E16817139005
I think I may have an old power supply laying around I may try. But it might be to old.

EDIT:: fixed. Looks like the main motherboard power connector had vibrated loose a little which aloud only the power supply and hard drive to turn on. Tragedy averted. I checked all the connectors, it looked plugged in, but after thinking about it, it only made since that that was the problem.