Antwort auf „Do I need to buy a logic board?”I'm having the same problem with the same imac I have. Took it to a computer store, they took it in the back, came back and said, "it's the logic board", and it would cost me about $500.00 dollars to replace it, it's no good, just throw it away. The power supply is powering up, and working fine. I have tried steps #1 #2, and #3, and I don't see any progress from trying them. It still won't boot up, and the screen is still blank. The fan is turning and the power supply is working fine. What should I do? Trash it, or keep looking around until I find a solution?