20" iMac wont start up now.


I bought a 1.8 20inch iMac back in late April 2005. I havent had one single problem with it up until yesterday. I shut my machine down before I went to bed. I go to work the next day and when I got home last night and powered it up I heard the little "chime" or whatever it is when you power up a mac but the screen stayed gray with no apple logo in the middle. I rebooted it again and the same thing. After about doing this 3 more times I put in my OSX CD that came with my machine and held down "C" so it would boot from the CD. The OSX installation started and just to see if I could see the hard drive I went through the installation steps. I didnt actually re-install the OS though.

When it got to the stage where you choose a volume to instal it on it showed my super drive and the HD. I exited out and went into my disk utility. I tried to get it to verify the volume but it failed saying it could not unmount the volume. I tried to even erase it and it just sat there in a continuous loop. So I rebooted once again and used the install again just to see if it would show the HD this time. it did. It showed my 160gb HD as a volume I could install OSX on..but I didnt re-install it. The amount of HD space free (which is like 120GB) told me that all my stuff was still on my HD, so I rebooted one more time and my OS actually booted up and there i was at my desktop with everything intact, or so I thought. I opened up some applications and everything was working fine so I shut my machine back down and went to bed. Out of curiosity I booted it back up this morning before I left for work and the same problem reared its ugly head again. It went to a blank grey screen, no apple logo, no little status thing underneath it, it just sits there. So I put the OSX disc back in and rebooted, pressed "C" and went to Disk Utility again, this time its not even showing my HD, just the superdrive. I want to pull my hair out. All I use this machine for is work. There are no games or no unesscessary "doo dad's" or what not installed on it. Just Photoshop, Flash, etc.
Sounds like your hard drive is going or gone. I'd keep trying to start the iMac up again. If successful, copy all your data off the hard drive to DVD's using your superdrive. If you can't get it going, try starting it in Target Disk mode (Hold 'T' at startup) then use a FireWire cable to connect it to another Mac. Copy your data off to this 2nd Mac and burn it to DVD's or an external drive or iPod (whatever you have).

This iMac is under warranty and the hard drives are a known problem. It's probably a heat related issue. You'll need to get the HD replaced. That's why you need to get your data off first if possible.