My iMac has a blue screen and not continuing to the desktop, Help please.

[Liam Coultas]

I had recently come back from 1 week away and I turned on my Mac and it turned on normally, except it took about an extra 2 minutes that what it did usually. It then couldn't open anything and it just stayed at the rainbow wheel spinning, so I reset it. When I restarted my Mac again, it took about 2 minutes at the white screen (can hear my tone thanks to command option r) and then at the blue screen and the black spinning load icon disappears and comes back every 10 seconds. What can I do to get it working normally again?!

[DeadEndAccount]

  On 17/05/2013 at 11:23, Liam Coultas said:

I had recently come back from 1 week away and I turned on my Mac and it turned on normally, except it took about an extra 2 minutes that what it did usually. It then couldn't open anything and it just stayed at the rainbow wheel spinning, so I reset it. When I restarted my Mac again, it took about 2 minutes at the white screen (can hear my tone thanks to command option r) and then at the blue screen and the black spinning load icon disappears and comes back every 10 seconds. What can I do to get it working normally again?!

Are you able to force it into internet recovery mode? have you run the diagnostic test?

[Brian M. Veteran]

Boot with CMD+V held, and tell us at which line it stops (any money says it's something along the lines of "Invalid B-Tree".

TBH, it sounds very much like a failing hard drive.

[msr714]

Sounds like a failing hard drive to me, too.

[Liam Coultas]

It just said to me alot of stuff, in this picture it'll hopefully tell you if its not too blurry, if it is ill try and remember it off by heart as it instantly goes to a white screen after it inputs the last line.

[mwc]

Seems like a kernel panic but nothing about the kernel itself...

[vcfan]

BLUE SCREEN OF DEATH

[Liam Coultas]

So what should I do? Any ideas?

[DirtyLarry Veteran]

Think you should try the following. Taken from here...

How to Change Startup Drive Permissions If You Don't Have Another Startup Device Available

1. If you don't have another startup device to use, you can still change the startup drive's permissions by using the special single-user startup mode.
   
2. Start your Mac while holding down the command and s keys.
   
3. Continue to hold both keys down until you see a few lines of scrolling text on your display.
   It will look like an old-fashioned computer terminal.
   
4. At the command prompt that appears once the text has stopped scrolling, enter the following:
   mount -uw /
   ?
   
5. Press enter or return. Enter the following text:
   chown root /
   ?
   
6. Press enter or return. Enter the following text:
   chmod 1775 /
   ?
   
7. Press enter or return.
   Enter the following text:
   Exit
   ?
   
8. Press enter or return.
   
9. Your Mac will now boot from the startup drive.
   

If you still have problems, try repairing the startup drive using the methods described earlier in this article.

[Liam Coultas]

  On 18/05/2013 at 01:25, DirtyLarry said:

Think you should try the following. Taken from here...

How to Change Startup Drive Permissions If You Don't Have Another Startup Device Available

1. If you don't have another startup device to use, you can still change the startup drive's permissions by using the special single-user startup mode.
   
2. Start your Mac while holding down the command and s keys.
   
3. Continue to hold both keys down until you see a few lines of scrolling text on your display.
   It will look like an old-fashioned computer terminal.
   
4. At the command prompt that appears once the text has stopped scrolling, enter the following:
   mount -uw /
   ?
   
5. Press enter or return. Enter the following text:
   chown root /
   ?
   
6. Press enter or return. Enter the following text:
   chmod 1775 /
   ?
   
7. Press enter or return.
   Enter the following text:
   Exit
   ?
   
8. Press enter or return.
   
9. Your Mac will now boot from the startup drive.
   

If you still have problems, try repairing the startup drive using the methods described earlier in this article.

Ok I did that and then some other text came up as shown in the image, and then it wen straight to white screen, then 2 minutes of waiting, back to blue, and now its going from black to blue over and over

[+jamesyfx Subscriber²]

I don't really see any error messages on any of those pictures here, so it's difficult to diagnose the problem.

Quickest thing to do would be to get your OS X disc and run Disk Utility from it.

Failing that, a re-install.

If it's a hardware issue, then you will have to get it repaired.. which is no easy task. :/

[Liam Coultas]

  On 18/05/2013 at 16:05, jamesyfx said:

I don't really see any error messages on any of those pictures here, so it's difficult to diagnose the problem.

Quickest thing to do would be to get your OS X disc and run Disk Utility from it.

Failing that, a re-install.

If it's a hardware issue, then you will have to get it repaired.. which is no easy task. :/

Should I have this OS X disc or do I have to buy it..? And if so, how much?

[Shadrack]

If it is still under warranty I would recommend taking it to an Apple Store. If your Mac came with and optical drive then it should have come with an OS X disc. Otherwise, you can contact Apple support to see if they will give you a replacement disc for your Mac.

Do you have a time machine backup on an external disk? If you do and it is setup correctly you should be able to boot from that.

Umm... I generally always have a backup, but if my hard disk crashed and I couldn't even get a recovery console open to reinstall OS X Mountain Lion or boot from my Time Machine backup I would probably "find" OS X "out there" and then reinstall it (probably via a bootable usb drive that I create on another computer).

[cooky560 Veteran]

If it boots fine off a time machine backup, or a USB disk (such as a linux partition on bootable usb) then try restoring the internal HDD from the time machine backup, you can do this either by booting off the Time Machine drive, or by booting off the OSx setup CD. If this fixes the problem great! If not you need to run the Apple extended hardware test (insert iLife CD and hold CMD +D) (this takes a LONG time), if any of the Apple Hardware test fails, take it back for servicing / replace the HDD.