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TS2570: Mac OS X: Gray screen appears during startup

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TS2570 iMac won't boot, GSOD with Flashing Question Mark, safe/verbose mode not possible

2168 Views 14 Replies Latest reply: Oct 20, 2012 1:59 AM by Neville Hillyer RSS
ryanwelmans Calculating status...
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Jun 24, 2012 3:25 AM

I have an iMac 24", just over 2 years old running OS X v10.5 (Leopard). Mighty Mouse and bluetooth keyboard, no peripherals.


It slowed enormously over the last few weeks and has now ceased to boot.


On switching on I hear the chime (blank grey screen initially), the grey screen hangs for approx 30sec before the flashing folder/?mark icon appears.

There is no further progress.


Boot key combination results:


  • Can reset NVRAM (Option-Command-P-R)


  • Cannot boot to safe mode
  • Cannot boot to startup manager
  • Cannot boot to verbose mode
  • Cannot boot from target media (DVD etc)
  • Cannot boot to AHT mode
  • Cannot boot to single user mode



I have followed the steps here


Disconnect, test peripheral devices and network cables - done - de-powered and rebooted. No difference.


Perform a Safe Boot- this does not work.  I am familiar with the boot combinations and timings. The safe boot leads to the same flashing folder/?mark icon. I have also tried verbose, single user, AHT and startup manager with the same result.


Reset the NVRAM / PRAM - done - this worked and kicks the system into an auto-reboot after 3-5 seconds. This also demonstrates the Keyboard is fine. The subsequent boot fails at the same point via normal, safe or verbose boot instructions.


Start from your Mac OS X Install disc; use Disk Utility – I never received an OSX install disk.  I have the original box with receipts etc, the only disk present is an unsealed version of iLife (yeah thanks Apple).  Where would I get one?


Check your cables and power source – done - all fine.


Remove third-party RAM and internal hardware – not applicable.


Perform an Archive and Install installation of Mac OS X – how would I do this when I cannot boot the device?


Perform an Erase and Install installation of Mac OS X as a last resort – how would I do this when I cannot boot the device?


To me the problem looks like a HDD failure.  I had windows (dual boot) professionally installed when I bought the iMac and since the Windows boot option is also not visible (startup manager itself does not work) I suspect the system can’t find bootable media because the HDD isn’t spinning.


An OS corruption would generally affect one or the other but presumably not both Operating Systems simultaneously.


It's hard to be certain, but I’m sure it used to make more noise.

I had a look into opening it up and troubleshooting the physical components but it’s hard to know where to start.  There are no obvious ways in and I’m not a professional so decided to post a question here rather than hack it open.


I'd be grateful if you could suggest next steps here, or is it time to go dig a hole in the garden?  I certainly expected more than 2yrs life from a £1200 unit.


Many Thanks,


iMac, Mac OS X (10.5.8), 2 yrs old, 24"
  • roam Level 6 Level 6 (13,545 points)

    Hi Ryan,


    Did you buy this Machine secondhand, because a Mac  running 10.5 would be closer to three years old.


    If you have Applecare a two year old Mac would still be covered if you think it is the HDD.


    It would be highly unusual if the OS discs were not in the box, so have a second look.

    If you still can't find the DVD, it would be possible to request from Apple a replacement set for your particular model. You will need to have all the details handy and it will cost you something I believe, but I can't say how much.


    If you think it is the HDD, alternatively, you could borrow someone else's 10.5 disk and boot from it just to see if Disk Utility can possibly repair your machine.

    Another possibility is connecting your Mac to another Mac in order to run the second one's Disk utility to do a Repair operation on your first one. The second one would need to be running 10.5 as well.


    I would not dispose of it even if it needs a new HDD,  as you have a great screen so it would be worth keeping alive.


    When it was slowing down over the past few weeks did you get any message that the disk was getting full? Not that this would help you now, but I'm just musing on the cause of the problem.

  • Neville Hillyer Level 4 Level 4 (1,845 points)



    It does not look good.


    It is relatively rare for Apple disks to fail so soon but a hard disk can fail at any age. For those who wish to spend time and money the best disk buying advice I can give is to always buy server grade disks with a 5 year guarantee. In general they will last many times longer than cheaper disks with a 2 or 3 year guarantee.


    I recently wrote long replies for another user. Some of my remarks may help you:


    Welcome to the unusual name club. Are you far from me? I live in Bedfordshire. From Google I suspect you work in London.



  • Neville Hillyer Level 4 Level 4 (1,845 points)

    It is too far for me to go to assist you but there are many people in London with old versions of OS X.


    After reading my link are you convinced your old drive needs replacing?


    Would dumping the old disk result is serious data loss?


    From the link you gave I assume your drive should be 3.5 inch like:


    In recent years I have bought both Western Digital and Seagate but I prefer my Seagate ST3750640NS. Further details at: S/SATA/100424667b.pdf


    I can see no reason why one of this Seagate range should not match your requirements but it might be as well for you to check the specifications.


    You are unlikely to get these higher quality enterprise drives in the high street but once you have a part number it is easy to Google for it.


    Good luck.

  • Neville Hillyer Level 4 Level 4 (1,845 points)

    (1) Are all 3.5 inch drives generally built to the same dimensions? Sounds obvious but perhaps there are height options to consider.


    The height of some old ones varied considerably but most newer ones are similar but it is best to check the specification yourself. The Seagate site has very full specifications.


    (2) I believe the current drive is SATAII, am I okay upgrading to SATAIII?


    Yes but data will only transfer at the lower SATA 2 rate.


    Assuming a green light on the above points it sounds safe enough to order this HDD and crack on with the installation.


    I would not buy this one unless I could establish it is an enterprise drive with a Seagate 5 year guarantee - this appears unlikely.


    From a quick look at the Seagate site it appears that they may have changed the names of their enterprise drives. In particular it appears that the Barracuda name is now used for desktop drives with shorter guarantees. I advise going to their site and examining their enterprise drives which used to have, and hopefully still do have, 5 year guarantees. They will certainly cost more and may not be available in such high capacities.


    Everybody should note that Seagate took over Maxtor makers of some of the cheapest and most unreliable drives. Not all Seagate drives can expected to be very high quality - take care - guarantee length is the best guide.

  • Neville Hillyer Level 4 Level 4 (1,845 points)

    Good luck - please say how you get on. I had a quick look and found:


    Nearline products shipped on or after December 31 2011 have a 3-year limited warranty. Nearline products shipped before December 31 2011 have a 5-year limited warranty.


    This is a pity. After the demise of MTBF (by silly exaggeration based upon bad engineering assumptions) in the disk industry a 5 year guarantee was, for many years, the best way to judge quality and probable life. In my experience lesser periods historically resulted in average life being reduced to about a third.


    All OSs after Leopard require Intel which I assume you have. Snow Leopard should run well and is inexpensive. Lion appears to have more problems than most Apple OSs but many people like it.

  • Neville Hillyer Level 4 Level 4 (1,845 points)



    Has your Mac got a fan?


    If not it would be wise the check the average power consumption of any replacement hard disk and make sure it is not excessive compared with the original one. A 50% increase is probably OK but I would be concerned if it is twice as much.



  • Neville Hillyer Level 4 Level 4 (1,845 points)

    Don't throw the old disk away. You may be able to get it to work. Even if it does not work in the iMac there is a slight chance of it working in an external enclosure. I assume it still has data you would prefer not to lose.

  • Neville Hillyer Level 4 Level 4 (1,845 points)

    Well done.


    A few years ago I put a failed Mac disk in an external enclosure and reformatted it. It is still working! - This may be worth trying.


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