Hi.

I have IMAC 21.5"/3.06/2X2GB/500GB/4 which I bought in Jan/2011
I upgraded to OS X Mountain Lion, v10.8.2 (4+) on Sep/2012.
Serial # will be given upon request.

Symptom:
iMac can't boot the OS.

Sequence:
1. Power on (power button pressed)
2. Hear startup sound
3. See Apple logo
4. See loading icon (spiral)
5. Can't enter OS login screen (even after waiting 3 hours; still loading...)

Can you repair my iMac?

Hope to hear from you real soon.
Thanks.