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I downloaded Mountain Lion OSX three days ago. On start-up my IMac shows a black DOS screen. Must unplug the Mac to restart. Please help!

I downloaded OSX Mountain Lion three days ago. On startu my IMac shows a black DOS Screen. I must hard boot and it works. Does anyone have the same problem?

iMac, OS X Mountain Lion

Posted on Jul 29, 2012 8:23 AM

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46 replies

Jul 30, 2012 12:15 AM in response to garet245

Similar if not the very same issue with my late 2009 iMac since upgrading to Mountain Lion.


First time I've seen actual script - DOS-like text (well, Linux or UNIX or whatever it is) that only seems to appear from a cold boot.


First time this happened I held down the power button until the system restarted.


Second time around - and from a cold boot - I entered "/exit" at the prompt and the system appears to have continuted the boot process.

Jul 30, 2012 6:31 AM in response to garet245

That is a system crash called a "Kernel Panic", search Google for the awful truth. It usually means something is horribly wrong with either your hardware or installation. If it ran normally under 10.7, I suggest re-installing 10.8 on a clean wiped hard disk which should fix the problem. You may be able to boot up into recovery Disk mode to fix problems, search internet for more info.

Jul 30, 2012 7:13 AM in response to garet245

If you're getting a command prompt, it really sounds to me like you are booting into Single User (or Verbose) Mode (more HERE). try this...


  1. When you boot into the command like, type the word "exit" and press return. You should go back to OS X.
  2. If it happens again, do the same, then reset the SMC and the PRAM by following Steps #1 and #2 HERE.


The second option is Incompatible Login Items...


  1. Try booting into Safe Mode by following the directions HERE.
  2. Open System Preferences and navigate to System Preferences > Users & Groups > Login Items. Uncheck any items but take note of what's checked so you can add them back later if not the issue.
  3. Check to see if any startup items are located in HD > Library > StartupItems.
  4. Restart in normal mode to see if things are ok.

Jul 31, 2012 12:58 AM in response to Alfred DeRose

Many thanks Gnarlodious and Afred DeRose, it's nice to know there is support out there. 🙂


Today's cold boot appeared to run without issue today. What's changed? Last night I disconnected two external USB2.0 hard drives of the Seagate "GoFlex" and "FreeAgent" variety then ran "Repair Disk Permissions" of the Macintosh HD. Next, I proceded to browse the web the rest of the evening and finally shutdown the computer before bed.


After today's first cold boot I shutdown the iMac, reconnected the external drives and booted up once again. No issues presented themselves at this point.


I am currently verifying the two external drives which is taking a while.


I have no idea if verifying and repairing disks and/or their "Permissions" has any impact on events giving rise to the "Kernel Panic" issue.


Yesterday I had to inlude a forward slash "/" (or was it a backslash?) like this: "/exit". When I entered just "exit" (minus the forward slash) the cursor just returned down the the next line. I did not exit "DOS", hehe. 🙂


I have no idea whether the issue is truly resolved even though the system today just cold booted twice and will go take a look at those links you posted.


I just wanted to share my experience so far.


Many thanks once again. 🙂

Jul 31, 2012 3:41 AM in response to garet245

Same problem here.


I did an upgrade from OSX Lion to OSX Mountain Lion and I also get a black boot screen ONLY from a cold startup. If I type exit, my macbook pro (Intel based 2010) startsup normally.


I know I can do a clean install with Mountain Lion OSX, but that would be a lot of work for me.


Are there more people who have the same problem and does somebody has a clue how to resolve this???


Thank you for your help in advance. 🙂

Aug 6, 2012 10:35 AM in response to garet245

Same problem here...


"I did an upgrade from OSX Lion to OSX Mountain Lion and I also get a black boot screen ONLY from a cold startup. If I type exit, my macbook pro startsup normally."


I already made a clean install and it didn't fix anything - the issue still exists (on my MBP 5.1 late 08)


BUT: the most horrible thing is: I also tried to downgrade to 10.7.4 (it worked perfectly before the update to 10.8!!!) and after being back on 10.7.4 it also boots (cold boot) into single user mode...


Now I'm back on 10.8 again (the 2nd clean install) and waiting for a fix...


I tried everything (alls kinds of commands, permission rights and reset all PRAM NVRAM SMC... no luck!)


A friendly guy on the german applehotline told me (after 2h telling him what my problem is): "mountain lion didn't break your mac it must be a hardware error and your mac is out of warrenty - so have a good one...bye"


Maybe apple will bring an update to fix this because it is ofcourse a software error...


Best regards from Germany

Aug 7, 2012 7:34 AM in response to vonundzu

vonundzu wrote:


Same problem here...


"I did an upgrade from OSX Lion to OSX Mountain Lion and I also get a black boot screen ONLY from a cold startup. If I type exit, my macbook pro startsup normally."


I already made a clean install and it didn't fix anything - the issue still exists (on my MBP 5.1 late 08)


BUT: the most horrible thing is: I also tried to downgrade to 10.7.4 (it worked perfectly before the update to 10.8!!!) and after being back on 10.7.4 it also boots (cold boot) into single user mode...


Now I'm back on 10.8 again (the 2nd clean install) and waiting for a fix...


I tried everything (alls kinds of commands, permission rights and reset all PRAM NVRAM SMC... no luck!)


A friendly guy on the german applehotline told me (after 2h telling him what my problem is): "mountain lion didn't break your mac it must be a hardware error and your mac is out of warrenty - so have a good one...bye"


Maybe apple will bring an update to fix this because it is ofcourse a software error...


Best regards from Germany



I hope Apple brings an update too. I still have this problem. I also tried to do a clean install, which was a lot of work! So it must be a software problem.


I find it really annoying to get the black boot screen every time I do a cold startup! 😠


I hope more people who have the same problem post something here, to let Apple now that they have to do someting about it! 😉


Best regards from the Netherlands.

Aug 8, 2012 2:32 AM in response to garet245

Hi,


I had this problem, which was temporarily cured by resetting the PRAM i.e. it would cold boot fine once or twice, then return. I noticed in the black screen at shutdown that Sophus Anti-Virus was somehow related. I removed it from login items and the problem remained, so I just completely uninstalled it using the Sophus uninstall programme. This appears to have cured the problem for now. I've since seen that a similar problem was being caused by some other anti-virus software too. I'll be installing something simple, like Virex, now.


Hope this helps.


(Note that I've replied with the same comment to various similar questions.)

Aug 16, 2012 10:14 AM in response to p-smyth

Hi,


Ik did not have any anti4us installed.


I still have this annoying startup black dos screen Apple OSX Mountain Lion problem.


I contacted Apple and they told me they are aware of this problem and also told me to wait for the next update! 😉


So I hope this issue will be solved soon.


In the meantime I hope that more people with the same problem will leave a message here. The more people leaving a message here on this forum, the more urgent it will become to Apple!


Cheers!

I downloaded Mountain Lion OSX three days ago. On start-up my IMac shows a black DOS screen. Must unplug the Mac to restart. Please help!

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