Won't power up at all but fans can blow at full speed
yesterday I followed this guide to install an extra SSD:
But after finishing and reassembling the iMac would not power on anymore. Nothing at all. No fans. Nothing. So reopened it to check the diagnostic LEDs. Only 1 of them is on when the AC is connected. That could indicate a power supply problem. But if I connect the AC cable while holding down the power button then all fans will run at full speed, which to me suggests that the power supply is ok. Is the only conclusion that can be drawn that the logic board is faulty? Does anyone have any other suggestion? I can not imagine that I broke the logic board because I was very careful.
Is this a good question?