I installed a new heatsink yesterday, and everything was fine with it, although I did have to remove my motherboard to install the base for the heatsink. Reattached everything exactly how it was before, and started up...no hard drive. I've got three hard drives, so I tried using different USB ports on the motherboard, no difference; tried changing the USB leads and power leads, no difference.
I'm wondering whether there is any possibility of being able to get the data off the now defunct drive...I've got a lot of work on there that I don't have recent copies of and the Mrs isn't happy that we've lost all the holiday pictures either.