IMac keeps shutting down during startup loading bar under apple sign

Question

My electricity went out and came back on a minute later. When my computer started up again the font was back to original factory setting. I then restarted my computer and every time it would load up it would shutdown. The computer chimes and then reaches a grey screen with an apple sign. Below it is a loading bar. This bar loads about 10% then goes back down and loads from 0%. A couple minutes later it shuts down after staying at 0%. It keeps doing this routine every time I start the computer. I then did a command s and rebooted the computer to factory reset it. The computer still shuts down and has the old habit of reaching 10% and 0% with the loading bar but now after the loading bar is at 0% it then disappears to the Apple sign and a loading circle. It then shuts down again. This iMac was originally 10.6.8. but i believe i updated it to 10.9.4 and was purchased new around 2008. I also tried to put in a CD with Firmware Restoration CD 1.7. but that didnt work. Can anyone help? or has anyone had similar issues?

Answer 1

Hello canwary
Good job on troubleshooting your issue so far. For most issues that deal with your Mac not starting up, consult the article below to see what the issue could be. 
Mac OS X: Gray screen appears during startup
http://support.apple.com/en-us/TS2570
Let me know if this helps,
-Norm G.