Powers ON, Chime, Black Display but external monitor shows video.
I have a 24" iMac 2007 2.4GHz which turns ON to a black display. I have done a lot of research and have looked at many guides to determine the exact issue and fix. I will explain everything i have done to troubleshoot but without a resolution.
Below you will see my troubleshooting has confirmed that both the Video card is in working order and the LCD screen is in working order.
I have hooked up an external display and turned ON the iMac and to my surprise I was able to see video on the external display. So this means my graphics card is in working order.
I removed the glass and aluminum frame and looked at the 4 LED lights and when powered ON all of the 4 LED's are solid green. So that means everything is communicating with each other like Power Supply, LCD Screen, Video card and Motherboard.
I decided to swap the LCD screen out with another iMac that i own (same EXACT model, specs and year iMac & same model # LCD screen). To my surprise the LCD remained black when i turned ON the iMac. This is a known good working LCD screen since it was removed from a fully functional imac. So i decided to swap the original screen from the 1st imac that doesnt display to the fully functional imac and i was able to see video on that screen. So now i know the actual LCD is in working order too!
At this point i am stuck and dont know what the issue is and what more i can do.
I was able to determine the Video card to be in working order by using an external display and i was able to confirm the LCD works by swapping it into another iMac system.
What else can i try to troubleshoot it in order to get this iMac to work again?
Please help me
Is this a good question?