Mac users help pleaseeeeee!

[Macette]

Hi, I got a white screen this morning when I came down stairs. After a google got to disc utility and ran it the answer was incorrect thread number and disc utility could not repair it.....Waaaaaaa! I am at my wits end ...don't know what to do.....help pleaseeeeeee it is an iMac running 10.8 mountain lion 3 and half years old....no problems till now. I have time machine backup on WD external ...just do not know how to proceed from here. At the moment it u plugged.

[Helen]

try this

1    Shut down your Mac.
 2  Locate the following keys on the keyboard: Command (⌘), Option, P, and R. You will need to hold these keys down simultaneously in step 4.
 3 Turn on the computer.
 4 Press and hold the Command-Option-P-R keys before the gray screen appears.
  5  Hold the keys down until the computer restarts and you hear the startup sound for the second time.
    Release the keys.

even if it does reboot (this is resetting the PRAM) please get the computer checked out 

[kalami]

try this

1    Shut down your Mac.
 2  Locate the following keys on the keyboard: Command (⌘), Option, P, and R. You will need to hold these keys down simultaneously in step 4.
 3 Turn on the computer.
 4 Press and hold the Command-Option-P-R keys before the gray screen appears.
  5  Hold the keys down until the computer restarts and you hear the startup sound for the second time.
    Release the keys.

even if it does reboot (this is resetting the PRAM) please get the computer checked out 

Omg how do you know things like this??
We've got MAC problems too.
I'm going to see if this works for us too

[Helen]

Because I've had mac  problems in the past too 

[BobnDot]

Incorrect thread number is indicative of directory damage on the hard drive. If you're running 10.8 you should already have a restore partition on your hard drive. It's a hidden file so won't appear anywhere on your desktop.
Restart your Mac and hold down the alt key (To the right of the ctrl key). If a desktop appears it'll likely allow you to click on the restore partition so that you can then access your Time Machine backup to restore your system. If there's serious disk directory damage this may not work and you'll need to start your Mac from a system DVD or USB drive.
Unfortunately it's not possible to boot your Mac directly from a Time Machine backup, it must be restored to a hard drive connected to your Mac.
For future reference you may like to look at a free (for the basic version) application called SuperDuper. This allows you to create a bootable backup of your hard drive which can then be used to start your Mac even if the internal hard drive is completely unserviceable. It works alongside Time Machine if required and can even co-exist on the same hard drive as your Time Machine files.

Now for the good news......There have been a batch of faulty hard drives found in certain iMacs and Apple will replace free of charge any such drives within a certain time. Check with the Apple support site for details.   http://www.apple.com/uk/support/imac-harddrive/

Hope you qualify.

Bob.

[JohnK]

I had my hard drive replaced under a recall. Yesterday I took my MAC in to have a faulty optical drive replaced and they discovered the screen had partly failed so replaced that too. So glad I have Applecare as it would have cost £375!

[Macette]

Incorrect thread number is indicative of directory damage on the hard drive. If you're running 10.8 you should already have a restore partition on your hard drive. It's a hidden file so won't appear anywhere on your desktop.
Restart your Mac and hold down the alt key (To the right of the ctrl key). If a desktop appears it'll likely allow you to click on the restore partition so that you can then access your Time Machine backup to restore your system. If there's serious disk directory damage this may not work and you'll need to start your Mac from a system DVD or USB drive.
Unfortunately it's not possible to boot your Mac directly from a Time Machine backup, it must be restored to a hard drive connected to your Mac.
For future reference you may like to look at a free (for the basic version) application called SuperDuper. This allows you to create a bootable backup of your hard drive which can then be used to start your Mac even if the internal hard drive is completely unserviceable. It works alongside Time Machine if required and can even co-exist on the same hard drive as your Time Machine files.

Now for the good news......There have been a batch of faulty hard drives found in certain iMacs and Apple will replace free of charge any such drives within a certain time. Check with the Apple support site for details.   http://www.apple.com/uk/support/imac-harddrive/

Hope you qualify.

Bob.

Hi Bob, I just checked my number and I didn't qualify mine is a 500 but thought I would try. My 3 year warranty was just out in January . I did try holding the alt key and all I get is a white screen with a progress bar when that fills it disappears and the spiral just keeps going. I did make a bootable super duper clone on the same external as my time machine backups but could not boot from that either just the same white screen. My problem is Apple are so far away from me so makes it impossible to Get the mac to them. Does it sound like the HD is gone. I even had some advice on the forum to try booting into Apple servers holding D and nothing happened just the same screen . I did get into disc utility once and ran the repair and that's when I got the message disc utility couldn't fix it. I don't know if I could wipe it if I could get to disc utility again and reinstall and don't even know if it would help anyway. I have no tech knowledge and I'm at my wits end. But want to thank you all for replying in my hour of need. if anyone can think of any thing else please post.

[BobnDot]

Unfortunately hard drives do have a limited life due to their reliance on a spinning disk, motor and moving read/write heads. Directory damage can be due to corruption of the logical data structure on the disk or to a mechanical fault in the drive, usually drive failure is a bit of both.
Making a bootable clone of an already damaged system isn't really going to work so I'd start off by booting the Mac from its original system DVD. If this works then run Disk Utility from the Install DVD. If your Mac boots correctly from the system DVD and Disk Utility is unable to effect a repair then you'll be looking at a replacement hard drive which, on an iMac, is best done by Apple or an Apple authorised repairer as it involves quite a bit of stripping down including the removal of the screen.
If you can get it to boot from the system DVD then it's possible to do a reformat of the hard drive and then re-install the system but, to be honest, with a 3+ year old drive already showing directory errors I'd certainly plump for a replacement drive and, as a large part of the cost is for labour, use the opportunity to have a larger capacity drive fitted or go for a solid state drive with no moving parts but a much bigger price tag.

Bob.

[Macette]

Thanks Bob I am taking your advice, I have priced a replacement HD with an authorised Apple repair business and he said £145 roughly for 500gb then for the 1 TB it is only an extra £10 or so. I have been trying to find out how much   will charge with no luck. Have rang Belfast store who didn't know then was put through to tech support and AppleCare and he didn't know either. I have an appointment on Saturday with the Genius Bar and would like to know the cost of replacement HD, because if its a good bit more i could cancel the Genius Bar and just get it done with the authorise dealer....

[Macette]

Forgot to say Bob I made the bootable soon after I installed mountain lion when it first came out and have never used it since . The apple authorised repair man said he would put all my stuff onto the HD from my external....

[BobnDot]

Thats a very reasonable price you've got there and I'd go for it especially if he's going to restore your files as well. Being an authorised repairer he'll be able to give it a good check out before proceeding with the repair and you should get a warranty on the new drive as well.

Hopefully that'll be you up and running soon.

Bob.

[Macette]

Big news mac fixed not broken HD..... corrupted so had to be wiped and backup installed home tomorrow yayyyy. Mac lives onnnnnn.........