Chosen Solution
I have a iMac 24" (A1225) which will not power on anymore. power on button gives no responce. Looking at the status LED’s i have the following behaviour: Power cord connected. LED 1 is on. pressing power on button, LED 1+2+3 is on, fan starts running, then after 2-3 seconds all LEDS out. iMac does noting. Also LED1 stays out. After taking of the power cord en reconnecting it LED1 is on again and the whole sequence can be repeated. Is this a power supply failure? or a logic board failure? Update Unfortunately not. it looks like this: http://www.super-laptop-parts.com/apple-… Update Model MID 2007 Modelnr: A1225 EMC no: 2134 last digits of the serial nr: ZCT Update Update:: I had no boot chime. Just the LED sequence as mentioned above. I removed the videocard and now it is giving me the boot chime. And it stays on ! So i think a new video card is the answer. Can i put a GT130 card in this machine ??
Power supply defect new power supply and it is running again !!
Does the PSU look like this? If so THIS GUIDE may assist in testing the PSU voltages.
I Plug the iMac in, LED 1 would light up; press power button then LED 2, 3 and 4 would turn on then all LEDs turn off. I then tried unplugging the inverter (and Video cable to the LCD)… I got it to boot with external screen and will replace the power supply.
