Previous 1 2 Next 15 Replies Latest reply: Apr 18, 2007 9:15 AM by MGW
teecee Level 1 (5 points)
First the problem:

I've had the imac G5 for nearly two years and its been running without a problem, now it suddenly wouldn't start up. Firstly I get two or three grey screens in succession looking as if being drawn from top to bottom very quickly, then the apple logo and timer, after a minute or so the fans start up to full power and it stays that way.

What I've tried:
Reading around discussions I tried rebooting from DVD installer and using disk utility. Result: error message: The underlying task reported failure on exit. 1 volume could not be repaired because of an error.

Because I want to sell the imac I had backed up all of my important data so I zero-wrote the hard drive in preferrence to buying a third party repair package. Reinstalled from DVD. Shut down and restarted. Everything worked except those banding grey screens appeared that were never there before. Something looks wrong. Then when i tried to reinstall microsoft office (as a test) the OS seemed to freeze and I had to shut it down again. Now it won't boot up as before. This looks like a very serious problem.
I hesitate to buy tech tool pro in case that doesn't solve it either.

Can't think if I did something to cause this. All I've been doing is transferring some data via ethernet to a newer mac. There was also a Lacie firewire drive linked to both computers as i was backing up stuff. One night I shut the iMac down and the next day it started with this problem.

Well... any educated suggestions would be most welcome,


By the way, the memory in the mac was purchsed from a third party and installed ages ago by myself. Never been a problem with it and have been running Final Cut Studio no trouble.

iMac G5 2GHz   Mac OS X (10.4.7)   RAM 2GB
  • MGW Level 7 (27,025 points)
    Have you verified the HD? It sounds to me as if it's failing. Try booting with no peripherals, try resetting the SMU and the PRAM, but I do think it's the drive (unless it's the power supply, but in this case, I don't think so).

    Please post back,

  • teecee Level 1 (5 points)
    Hi Miriam,

    tried both of those. No joy. I already unplugged all peripherals except mouse and keyboard.

    To correct my earlier description when the apple logo appears there is no timer, just the logo, then the fans.
  • DaddyPaycheck Level 6 (16,030 points)

    I am with Miriam, it sounds like the drive.

    If you are handy, you can buy a new drive and replace it yourself. It will be a nice feature when you go to sell it.


  • teecee Level 1 (5 points)
    the computer comes on. I did verify the disk after erasing it and re-installing OSX and it passed with no errors, but after sticking the MS office mac CD in the optical drive things went wrong again. The CD is original i.e. not a crack. And those grey effects at beginning?

    So you think it would do no good trying a third-party repair kit? I'll realy have to buy a new drive? It sounds drastic. Why would it fail so suddenly out of the blue?

    thanks for help.
  • MGW Level 7 (27,025 points)
    Things to do fail out of the blue, a new drive is probably cheaper than buying TechTool or Diskwarrior. Have you run Apple Hardware Test from the install disc? That might pin-point something, but I doubt it.

  • Marcusa Level 1 (0 points)
    I am beginning to see these symptoms. Disk Utility (from startup DVD) can't repair because "1 HFS volume checked"
    "1 volume could not be repaired because of error"

    Am I looking at replacing HD or is there something else that I can try?

    iMac G5 nosight   Mac OS X (10.4.9)   2005
  • Eugene Morse1 Level 1 (0 points)
    Long story short, I had the same problem last week, just after installing the latest software updates. I went through all the resets and disk utility verification (multiple times with phone support -- Apple Care), then took it to the local Apple store b/c nothing worked. They couldn't figure it out either and recommended that I try to backup my data on my bootable external drive before they started messing with my hard drive, since Apple stopped providing this service. I brought it home, could not boot from my external drive, so booted from the disk again, just for kicks I ran the same verification process (this was the 3rd or 4th time). This time something happened but it still failed. So I ran it three more times (each time something new happened and then it failed, until the third time when everything worked. The only problem now is that I seem to have lost all sound???? I did immediately make a duplicate of the Imac hard drive. Any thoughts on how to get my sound back? hope this helps....

    Imac G5 20"   Mac OS X (10.4.9)  
  • Rod Hagen Level 7 (31,985 points)
    Hi teecee,

    What happens now if you boot from your OS DVD and run diskutility to "repair drive"?

    The original "exit on failure" messgae may actually not have been all that serious. There are various circumstances which can produce this message without a problem of any consequence existing. See down the bottom of for example.

    I wouldn't give up on this one yet.

    Have you tried wiping the drive again and simply re-installing the OS? THis should achieve anything which a third party utility would be able to do anyway, in almost all circumstances.


  • Rod Hagen Level 7 (31,985 points)
    Have you tried PRAM reset for the sound, Eugene?

    You might also want to consider an "archive and Install" of the OS, as long as the computer is booting from your OS DVD successfully, after running "repair disk" and "repair permissions" (in that order) using Disk Utility while booted from the OS DVD.

    As you have a backup , reformatting, zeroing the drive, and re-installing from scratch is worth considering too.


  • teecee Level 1 (5 points)
    Hi Rod,

    This thread has veered off a bit. If you refer back to my original post, I stated that I had wiped the HD and reinstalled the OS. I did this following the guides on the apple support article, and did a seven pass 0-write erase (which should have sorted it out). After reinstalling the OS from the DVD it appeared to be okay except for the ominous grey screens at the startup. Then when installing further software the problem came right back as before.

    Tried verifying and repairing again from the DVD but same as before, same messages. First aid failed. I'm going with the 'requires new hard drive' theory at the moment but if you think of anything else in the meantime let me know.

  • Eugene Morse1 Level 1 (0 points)
    Thanks Rod,
    I did contact Apple online support after posting that message. (this was not an easy support to find)... they also suggested Archive and Install, which I did and it seems to have solved all of my problems. I was a bit timid to do it and I had to reinstall a bunch of updates and I'm sure I've lost some third party installs, but it does now work and the overall performance seems much improved.... I hope that has solved my issues or I hope if it does 'break' again it will be before my extended Apple Care plan runs out in November.... thanks again....
  • MGW Level 7 (27,025 points)
    As I said before, a new hard drive is really not expensive, and at least guarantees you a working machine to sell, and if you put a larger HD in it, you can easily recoup your expense.

    Let us know what you finally decide to do,


    P.S., if you'd like, go ahead and click the "Helpful" or "Solved" buttons on any of the posts / replies above if you feel they were helpful or adequately answered your question.
  • teecee Level 1 (5 points)
    My machine is now with a local engineer. They tested the hard drive before replacing it just to make sure that it was the hard drive that was at fault, but found it to be working perfectly okay. So they haven't found what the problem is yet. The system will start and restart okay apparently, but once you turn off the computer, then turn it back on that's when the problem starts.
  • teecee Level 1 (5 points)
    Finally it turned out to be the hard drive after all. thanks all, but wish I'd installed it myself, - labour cost me £30.
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