Chosen Solution
Hello everyone, I need help with this one as I am dreading the cause to be the graphics card again…. A week ago while using my iMac it made a “pop” noise - much like a capacitor breaking. The screen went black. Using a torch I could see that the LCD was indeed working, just the backlight of the LCD turned off. I went through the Technicians diagnostic steps. I’ve replaced the Backlight Board, no change. I’ve replaced the complete LCD panel, no change. This also changes all cables in the process. I have a feeling that the main power board might be at fault here, but the diagnostic steps end here. Can anyone tell me what voltage I would need to see and when at the Backlight Board power supply side? There are 6 pins, I understand that pin 3 should be live to enable the backlight?! Do I need the LCD connected to be able to take a valid measurement there?What kind of voltage do I expect?Are there schematics available to give me an indication? I’ve replaced the graphics card once already. I hope it is not due to it again (backlight enabling voltage etc…). Any input is mutely appreciated. Many thanks, Rob
Resolved by replacing power supply board.
