5 Replies Latest reply: Mar 30, 2009 10:15 AM by Carolyn Samit
andyman2 Level 1 Level 1 (0 points)

I recently came back from holiday for a couple of weeks and sat down to start my iMac (24" C2D). The machine just sat at a white screen and wouldn't go anywhere. Thought, ah, I'll just reset the PRAM (unplugged power cable for a min or so), and still same problem. Eventually I got the mac to boot by holding down the power button, the long beep sounded and the mac booted. All was well, until the next time I powered it down. Same thing, however same resolution didnt work...

After numerous attempts holding c, I've managed to boot into the mac installer, which said it couldnt repair the drive through disk utility. As I have time machine backup, thought I'll just start from scratch. Created a new partition (just to make sure everything was fresh), verified disk (no problems), started installer and it crashed towards the very end of the install (just over 1 hour in) with errors of being unable to copy files. After another few hours, managed to boot from CD again, this time install started, left it running overnight, only to find the mac in the morning on, but with a black screen. I've had to power it off and now I'm left with the same issue of a white screen and being unable to boot from CD.

Does any of this make sense to anyone? Could be a failed HDD, but why would I have the issue with the iMac generally refusing to boot from CD? Ran hardware diagnostic (extended) and no problems found.

I now have no hair left...

iMac, Mac OS X (10.5.6)
  • PT Level 7 Level 7 (20,880 points)
    I assume that model has a back up battery in it? If so, have you changed it recently? If not you may want to replace it. In the meantime, try removing it completely and see if it starts up any better. If the battery is right on the hairy edge of good/too low, it might be corrupting the PRAM (or whatever they call it now on new models) causing start up issues. If you remove it, you won't retain a lot of settings such as Date and Time, but you should also be able to boot up eat time with all default values.

    I had the same sort of issue with my eMac and pulling the battery cleared it up. That was many months ago and one of these days I might get around to buying a replacement battery... or not.

  • andyman2 Level 1 Level 1 (0 points)
    Thanks. Have a new drive on order, so if this doesn't work, will give the battery replacement (or removal!) a try.

  • Carolyn Samit Level 10 Level 10 (95,950 points)

    If you haven't done so, try resetting the SMC. http://support.apple.com/kb/HT1543

    Also, there are several disk utilities available that you might want to look into. One is DiskWarrior the other is TechToolPro

  • andyman2 Level 1 Level 1 (0 points)
    Thanks all, I've now fixed the issue. For those reading if you have a similar issue (there seems a few around the web), its the hdd. Useable to some degree but with bad sectors.

    Replaced hdd (using one of the several guides on the net), works fine. Can boot off cd no problems using select boot device. And this time didnt hang at all (think it used to hang when trying to check disk).

    Time machine now restored all onto drives. Working perfectly.
  • Carolyn Samit Level 10 Level 10 (95,950 points)
    Good news!