iMac 20" Not Starting, Motherboard or Video Card?

[iMavrick]

Hello everybody,

I have just been given an iMac 20" (2210) from 2008 that does not start. When I press the power button, I can hear the startup Chime every 5 seconds since it keeps rebooting. I can also hear the fans and optical drive. However the screen remains black.

I took it apart and I only have led 1 and 2 on. Both 3 and 4 remain off all the time. (led 3 is on for half a second when I press the power button)

As I am now trying to figure out if it is a motherboard issue or a video card issue, I am in need of your help since both parts can be quite pricy compared to the value of the computer.

The motherboard is a "820 2223 A" and the video card is an ATI "109-B22553-11".

Thanks in advance

 

[Intell]

LED 3 not turning on means the logicboard and video card are not communicating. You could try reseating the video card or replacing it.

 

[iMavrick]

Thank you Intell, but this is the answer I have been finding online all over, and it does not imply that led 4 is also off.

I am guessing the video card could be the problem, but I was just wondering if any of you have experienced this before?

 

[Intell]

Yes, I've replaced a few video cards that have failed like that.