imac 7,1 bad sysbd or power supply, hack needed?

[turboyoshi]

I have a 24" imac I bought new in 2007 and it recently died after a snowstorm caused repeated power cycles. It gets power, led1 stays on solid and led 2 and 3 blink every 3 seconds and led 4 never comes on. I suspect a bad system board. I'd like to fix it but paying $250 for a 7 yr old system board seems dumb. Even if it's just the power supply, I can't find them for cheaper than about $170. Can I get a similar board to work that's non apple? Are there better options?

Has anyone attempted anything like this?

Thanks for reading.