27" iMac doesn't boot past white screen, not-responsive
Yesterday, I was working in Autodesk Maya, and suddenly whole screen went black, so I did a hardware reset, by holding down the power button.
After that the iMac doesn't boot properly. It does the chime sound, then the apple logo with indicator and then just goes to a white screen. The keyboard doesn't work as caps-lock light wont come on.
I have tried the following:
- RAM reset (Cmd+Opt+P+R)
- SMC reset (unplugged power source for 2-3 hrs, held down power button for 10 sec)
- Removed ram cards and powered up, it did the SOS beep with 5 second intervals, so I'm guessing logic board is fine
- Holding down Option key during startup brings up the disk selector (I have 2 partitions one with Lion and one with Mountain Lion) neither boots up.
- Tried booting from an external Mountain Lion Install USB drive, it shows up in Disk Selector, am able to select it, but then it stops at white screen
- Ran a thorough Apple Hardware Test off the internet through ethernet cable, took 1:45 hours and it showed no errors
- Tried to run through Mountain Lion Recovery Disk, same white screen
- Entered sIngle user mode (Cmd+S) and ran fsck -fy on boot disk, it gave a few minor errors, so I repeated fsck -fy a few times until it no longer gave errors, still doesn't get past white screen. I'm able to browse the HDD in single user mode using the shell. Then did "exit" and also "reboot" commands, both ended in white screen.
I've looked around and found several guides dealing with this exact problem, but as you can see from the elaborate list above, none of those remedies have worked for me.
Any help is greatly appreciated, I'm on a tight deadline to finish this animation project and this is the only machine I have access to at the moment.
I don't have Apple care nor warranty and there's no Apple store/Genius Bar nearby.