10 Replies Latest reply: Mar 28, 2012 1:17 AM by Rafael Burgos
Rafael Burgos Level 1 (45 points)

With the upcoming shut down of MobileMe, I am in the process of migrating my intel mac to OS X 10.7


My Mid-2007 20 inch iMac is supposedly able to run Lion.  It has 4 GB of RAM.  It has been running Leopard 10.5.8 without problems thus far.  I did a clean install of Snow Leopard and then an in-place upgrade of Lion.  Since then the machine is unusable.  The machine boots and goes into a blank screen and sometimes will load the desktop.  When it does load the desktop, it will freeze with a spinning beach ball and no response for hours (I've left it on all day to see if the system will respond).  Graphics corruption and glitches are noticeable just prior to the freezes.


I then wiped the HD clean and installed Snow Leopard.  To my surprise similar problems were found.  I ran the AHT and did the extended testing and no problems were found.  Memory checks were good and no problems with the graphics card were reported.


I've done the usual PRAM / PMU reset and this does not help.  I've googled and searched the web and found some people that had similar problems but not exactly the same. 


As a last resort, I am posting this message to see if anyone in this forum has any helpful information or suggestions.


Thanks in advance.



  • Carolyn Samit Level 10 (102,825 points)

    HI Rafael...


      I did a clean install of Snow Leopard and then an in-place upgrade of Lion.  Since then the machine is unusable.

    Make sure your Mac meets Lion's requirements ...


    • Mac computer with an Intel Core 2 Duo, Core i3, Core i5, Core i7, or Xeon processor
    • 2GB of memory
    • OSX v10.6.6 or later (V10.6.8 recommended)
    • 7GB of available spare


    From here > Apple - OS X Lion - Technical specifications


    it does load the desktop, it will freeze with a spinning beach ball and no response for hours

    I then wiped the HD clean and installed Snow Leopard.

    To my surprise similar problems were found.


    If you have not done so, run Disk Utility. The startup disk may need repairing   >    Using Disk Utility to verify or repair disks



    edited by:  cs

  • Rafael Burgos Level 1 (45 points)

    Thank you for your response Carolyn.


    The iMac is identified by System Profiler as iMac7,1.


    The about this mac screen shows the following:

    Screen Shot 2012-03-22 at 8.25.57 AM.png

    Thus, I think it does meet the minimum system requirements.  The graphics card is not as capable as other model's but it should suffice for basic functioning.


    I cloned the disk from a MacPro (early 2008) to an external FW drive and booted the iMac from it.  I locked up shortly after attempting to log-in but I could see that the external drive's activity indicator was busy.  Left the machine alone to finish whatever it seemed to be doing at the moment and came back this AM and found it was showing all kinds of graphics corruption on the screen but surprisingly it was responsive to keyboard and mouse activity.  I rebooted and found out the machine is now working ... quite perplexing.  Will probably try to clone the external FW drive onto the internal drive of the iMac and see how it goes.



  • rkaufmann87 Level 9 (53,550 points)



    I think your problem isn't so much with Lion but the method you installed it. You did not mention what is installed on the cloned external FW drive, Snow Leopard or Lion so that is a little confusing. However you did mention the EHD's clone was created from a Mac Pro. I think the reason you are having issues is the clone has video drivers from the Mac Pro and not for the iMac which of course are totally different.


    To be honest it sounds like you have created a mess. I hope you have a sound backup of all the data on the iMac because I think you will need to start over. This time what I'd do is an erase and install of Snow Leopard (from a retail copy of SL), on the iMac. Then I'd install all the software updates to get it to 10.6.8 and restore all of your data from your backup and finally navigate to the Mac App Store and install Lion per the directions.

  • Rafael Burgos Level 1 (45 points)

    Thank you for your suggestions.  I did go through the (retail) Snow Leopard -> Lion upgrade path.  I wasn't able to get the machine to work that way. Freezes/graphics corruption were constant.  I even reinstalled using the recovery partition. I did perform a full-disk backup of the previous system (10.5.8) to an external USB drive for safety.


    The Early 2008 Mac Pro was used for the clone because it uses a similar graphics card and the drivers for one were at one time compatible with the other (in fact, I did an unsupported Tiger install on this mac pro using the drivers from this same iMac back in the day).  I upgraded the Mac Pro to Lion  (clean install of Lion using the App store download) and it has worked flawlessly.  This system is running 10.7.3 which is the one cloned to the external FW drive used to boot the iMac.


    I left it on while I'm at work and will check to see if it locks up or has any problems when I go back home in the evening.


    I'm keeping my fingers crossed that it will work.



  • rkaufmann87 Level 9 (53,550 points)

    Let's hope it does. Was the iMac totally stable on Leopard, the reason I'm asking is the way you're describing the way it's acting I was thinking it might be a hardware problem.

  • Rafael Burgos Level 1 (45 points)

    Indeed, the iMac was working without any noticeable problems with Leopard. I'm only trying to upgrade it to get iCloud functionality before MobileMe is history.

  • rkaufmann87 Level 9 (53,550 points)

    When you upgraded to Snow Leopard did you do a re-format and install? If so then it shoudl be working flawlessly unless your backup is in rough shape or the hardware is having problems.

  • cricketernot Level 1 (135 points)

    I have a mid 2007 iMac like yours. 3GB RAM Lion runs fine on an external bootable drive. Don't know much about Lion, don't really need it or want it but might be forced to us it at some point. What I'm actually using is Snow Leopard. There is this pressure to > Vorsprung durch Technik. Resist it.

  • Rafael Burgos Level 1 (45 points)

    I am posting this as a possible solution to the original issue, it may benefit others.


    The fact that Lion ran well when used from an external firewire drive but not from the internal SATA drive got me thinking about the possibility of permission issues that could affect the computer.


    I came across the following:  http://jrause.com/blog/?p=165 and followed recommendations from there and from the Apple discussion linked by one of the commenters at the bottom of the page.


    Bottom line:  I nuked the ACLs by going into Single User Mode (SUM).  First I used fsck while under SUM and by issuing the /sbin/fsck -fy command and verified that the file system was OK. Then I removed all the ACLs by issuing the command chmod -N -R /Volumes, finally I typed reboot and the machine magically worked as it should have.


    I was then able to log in and set up the machine.  No more freezes or lockups.  Sounds odd but I now have a functional iMac mid 2007 running Lion.  Now to the next task - migrate to iCloud!


    Have yet to run a permissions repair from Disk Utility to verify if the "fix" survives a permissions repair.  Will update when I do.

  • Rafael Burgos Level 1 (45 points)

    Solution found


    The solution to the freezes can be found in the following discussion and website.


    https://discussions.apple.com/thread/2384136?start=405 (this discussion spans a whopping 70 pages from March 2010 to the present)




    It seems that since Apple updated OS X from 10.6.2 all the way to 10.7.3 they have used video drivers that have caused problems to countless numbers of people.  It's been almost 2 years without an official fix from Apple and the "fix" presented is a hack that uses the video drivers from the 10.6.2 update and installs them in place of the drivers for 10.6.3 - 10.7.3.


    After applying the fix to my otherwise fully operational imac, I have had zero problems, zero freezes.  This is absurd!!!