Chosen Solution
I have I mac that i am working on when you try to power it on the fans are on, led 1 and 2 are on solid, led 3 flashes slowly, and there is no chime and the screen is black. I have seen posts on here if led 3 is not on but none if it is flashing. I don’t want to replaced the video card if that is not the problem.
Plug into an external monitor. If it works your video card is ok and the problem is in the internal display chain (cable, inverter, LCD). If the external monitor does not work it’s your card. If this Answer is helpful please remember to return and mark it Accepted.
