Did I fry my iMac? I pulled a old PowerMac G4 out of the corner and took a FireWire to USB adapter and connected to my iMac... yup, when I was doing it I know it was dangerous, but I did it anyway. Immediately my iMac went black and would not power up again. (Stupid, I know) I pulled the plug and held the power button for 10 sec... didn’t work... any suggestion or is it done?