Chosen Solution
hi i bought a broken apple imac 27 the system powers on but no apple start up sound and also the screen stays black. i tryed connecting to a external display but still does not work. i have looked at the diagnostic leds left of the ram slots with the screen removed and i just see 2 leds that stop on. anyone help please.
Hook the iMac up to a external monitor. If it still doesn’t work, it’s the video card. These iMacs should use a MXM graphics card. Here’s a guide on how to replace it. This is probably the cause of the problem in your computer. If this doesn’t fix it, then come back on the issue. If the video card doesn’t fix it, then I’d look into the screen. It’s usually not the screen though. However, it can cause this problem. If you wanted to check without a GPU, then shine a flashlight at the screen and see if you get an image. If you do, it’s probably the screen. If not, it’s a bad screen altogether or a bad graphics card.
