iMAC wont start

[WeLoveApple]

A1224 (EMC 2210)
It wont start at all. Only first diag led is on. When I want to turn it on the fan spins up for a second (quarter fanspin style) and at the same time the second lend blinks one time.
Tried with another good power supply. It does the same.
Ideas?

 

[aprendiz]

Short in any secondary power supply, usualy 5V on USB .........

 

[dukefawks]

Short on some secondary rail indeed. Fucked up reflowed GPU is also a common suspect. Check all rails for shorts.