My computer stopped working the other day. I came down and it was kind of chirping away. Then, when I restarted it, it only did the same thing.

I unplugged everything not needed and it did nothing at all. I thought maybe the power supply wasn't working, but when I took the cover off the green light on the motherboard was on and the power supply is making a little buzzing sound. But nothing happens when I turn the computer on, other than the green light on the motherboard flickers a bit.

I checked the memory in other computer and it works fine. I'd love to be able to fix this with as little cost as possible. Can someone here help?

P4-640 (3.2E GHz, 800 FSB, L2:2MB, EM64T, HT)