Screen black after boot, secondary display working
I got my hands on this core duo iMac; according to the previous owner the screen just suddenly died. He removed the RAM, so I put some new RAM in myself. I can get it to boot properly, and with an external display connected and mirrored displays, I can login and use the computer just fine.
Searching these forums I found that the issue is probably related to the GPU - is the secondary display not connected to the graphics card then? Are there any other options? Like the inverter or perhaps the display itself?
I also read that the graphics card is actually soldered on the motherboard, does that mean I'd have to replace the entire logic board, instead of just the GPU, as you would with non-mac PC's? Is there maybe some sort of diagnostic tool that can tell me what piece of hardware is failing?
Thanks for your answers.
Forget the graphics card, it's fine or the external monitor wouldn't work. Your concern is with the LCD, the inverter and the cables to them. Can you see the desktop at all? Do you get any type of light on the screen? Do you know if the previous owner or anyone else has been into it?
It turned out to be the inverter indeed! I ordered a spare via eBay, replaced it, and the screen is working just fine! Thanks for your help Mayer!
I have one minor issue though, in the corners of the screen, there is some color difference, there are some darker spots. I think it has to do with the shielding, as I ripped some of the aluminum tape when I took the iMac apart.