Opened up to blow out the case... now bricked

I used the guide on this site to open up the case on my iMac Core 2 Duo 17" 2 Ghz and remove the LCD to blow out the dust because one of the fans was making a grinding noise. After I put it together and plugged it in and pressed the button nothing happened... it's dead.

Tell me I can fix this somehow, I don't have the money for a new computer and my livelihood relies on it.

Last Three Letters of Serial Number: VUX

Led 1 is on, Led 2 is on when I press the power button. Led 3 doesn't come on. Can' find Led 4. Also, on this model the Leds are above the SATA connector, pretty far away from the RAM slots.