I just completed a replacement of my Mac's innards, including an upgraded HDD, a new SSD and a BD drive in place of the SuperDrive. And now my Mac is dead. It won't react to the power button at all. Swapping out the HDD and the optical drives was easy. However, adding the SSD was tough because the 3rd SATA port is on the backside of the motherboard and a bitch to get to. Having said that, I got everything connected up as prescribed, and everything fit back together (without any bits left over). I know this is a bit of a long shot but...has anyone else had a similar experience after opening up their iMac? It's either some forehead-slappingly obvious screw-up by yours truly, or I've done some damage while rooting around in there that will need professional help to fix. TIA.