So I'm in the market for a Power Supply because mine took a dump. Or at least I'm pretty sure it did.

What happened was, when I went to go turn on my computer there was a loud pop that came from the back of the tower and a few sparks flew out from where you plug in the cable to the power supply. It would not turn on since.

It originally had a 600w. But would I be able to get a less wattage power supply? Here are the specs.

Processor: AMD Athlon(tm) II X4 630 Processor, Quad Core 2.8 GHz
Memory: 4GB DDR3
Hard Drive: 500GB
Video Card: ATI Radeon HD 5670
Monitor: HP w1707
Sound Card: AMD High Definition Audio Device

So, unless any of you are willing to give me one for free, I need to find a the cheapest that will still work for this setup.
Please help. Links are recommended.