2009 21.5 iMac. After a very brief power fluctuation (sudden power loss , 3 second outage and the power came back) I attempted to turn my iMac back on. The iMac will chime, the Apple logo will appear and the progress bar will go across the screen until the veery end and then the computer will just stop. I have reset the PRAM and was able to boot into the disk utility and perform a a disk repair. but the iMac still shows the same issue. I am stumped. Any ideas?