Origineel bericht door: Vince ,
I'm jealous, I can't get the first LED to light on my 17". from what I have learned so far the I mac runs on three voltages - 5v, 3.3v and 12v for the inverters. If any of these are shorted out (go to ground) then the iMac shuts the power off. So you probably have a bad inverter or bad bulbs not a power supply problem.