08-16-2012, 06:14 PM
I'd turn off the imac immediately...you never know what programs or part of the OS will be writing data to a part of the disk that contains data you need. If you have another mac that can connect to the imac in Firewire target mode, that'd be the method I'd recommend to scan the disk with something like Data Rescue. I've had good luck with that program as well.