Powers ON, Chime, Black Display but external monitor shows video.
Hello,
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
Thank you
Is dit een goede vraag?
3 opmerkingen
Is it a backlight problem? If you hold a flashlight up to it can you faintly see the image on the screen? It takes getting just the right angle of the light and your view sometimes.
door Toupee Scalper
I dont think it has anything to do with the backlight or the LCD screen since i was able to swap the screen into another imac and verified the screen is in working order. I even placed a known good working LCD from another imac into it and it still didnt show picture.
Based on having a working LCD screen i dont think the screen is bad nor the backlight.
door Mike
I was thinking it may be the power supply circuit to the LCD. Lucky you have another iMac for parts testing! Try borrowing the Power Supply from the other iMac and see if that sorts it.
Another random idea would be to put it to sleep and wake it. I once saw an iMac that would only engage the LCD after waking. Probably not, but hey, worth a shot. Happy repairs!
door Toupee Scalper