Chosen Solution
Hi all, I was looking for some help to see anyone could point me in the right direction. My iMac 2011, 27” currently has no display output both with the internal LCD display or through an external monitor. I’ve also tested a second LCD display with no luck. The 4th diagnositic light isn’t on when the display is connected, but the other 3 are. The device boots with the chime and is accessible via SSH. When the display is fully disconnected the device will boot with the fans maxed out but doesn’t do this if it is connected (not sure if this helps). I have also tested multiple video cards, I’m confident this isn’t at fault either. If anyone could help I’d be extremely grateful, cheers!
If you can get to the system remotely that’s a good sign! But it doesn’t tell us for sure where the problem is. I would plug in an external display display does your desktop show up on it? If it does then your issue is within the display assembly. I’ve seen a few have problems within the T-CON board, replacing the assembly solved it. Here’s one source for the part 27” iMac Display Assembly, Apple P/N 661-6615
Could be a pram issue
