4 Replies Latest reply: May 6, 2012 9:41 PM by BDAqua
Kevin W. Suiter Level 1 Level 1

I have been having problems with my 2007 iMac for the last two weeks.  First, it began with the "White Screen of Death."  After a trip to the Apple Store & a fresh erase & reinstall of the system, everything was working fine...for 3 days!  While reinstalling programs throughout the week, the system started moving slower & eventually unusable because of how long it was taking for actions to occur.  Tried various ideas from searching the net, but to no avail.  Thought it might be my hard drive failing so I decided to go back to the Apple Store yesterday.  While there, the problem could not be replicated.  Everything worked fine & he said that everything looked great.  No major problems, tests all passed.  Got home, plugged everything in, fired it up & same problem as before!


I checked Activity Monitor today.  The biggies on CPU activity are "kernel_task" & "SystemUIServer".  When viewing the System Memory, I noticed something interesting.  The system memory was almost completely used up which is 4GB.  Hard Drive usage was fine, 250 GB free. 


Once I unplugged all USB devices & rebooted, I discovered that everything was working just fine.  I usually have a USB keyboard, USB MIDI Keyboard, and Firewall Maxtor External HD plugged in.  I have narrowed it down to the Korg USB MIDI Keyboard.  Without it plugged in, there was around 3.13 GB of free System Memory.  When I plugged it in, it immediately started dropping and ended at around 7 MB of free memory!!!  I've tried different cables and that did not resolve the issue. 


I would appreciate any ideas or suggestions!  I am completely stumped as to what the problem is.  I live 2 hours away from Apple Store...a 3rd trip is not possible this week! 




iMac (24-inch Mid 2007), Mac OS X (10.7.2), 4 GB Ram
  • BDAqua Level 10 Level 10

    Great work so far Kevin, I think we're on to it!


    Open Console in Utilities & see if there are any clues or repeating messages when this happens.

  • Kevin W. Suiter Level 1 Level 1

    Thanks BDAqua!  OK, opened up Console.  Cleared the log so that it would be fresh from when I plug the USB MIDI Keyboard in.  Here is what started to happen once plugged in:



    0     0  AppleUSBCDC: start - initDevice failed

    disk0s2: I/O error.

    (default pager): [KERNEL]: ps_allocate_cluster - send HI_WAT

    macx_swapon SUCCESS

    (default pager): [KERNEL]: ps_select_segment - send HI_WAT

    macx_swapon SUCCESS


    The log then goes on to repeat the last two lines, continuously about every 30-60 seconds. 

    (default pager): [KERNEL]: ps_select_segment - send HI_WAT

    macx_swapon SUCCESS



    Again, thanks for any help with solving this mystery!!!!


  • Kevin W. Suiter Level 1 Level 1

    Problem also occurred when I plugged iPhone into USB dock.  Seems to be associated with any type of USB activity, exluding the wired QWERTY keyboard.

  • BDAqua Level 10 Level 10

    Any Bus powered USB devices that do not have theor own A/C power?


    What all USB devices are connected?


    BTW,my 2007 iMac failed twice, 1st needing the PSU, HDD replaced, 1 week later needing the PSU replaced again.


    Hardware Overview:


    Model Name: iMac

    Model Identifier: iMac7,1

    Processor Name: Intel Core 2 Duo

    Processor Speed: 2.4 GHz

    Number Of Processors: 1

    Total Number Of Cores: 2

    L2 Cache: 4 MB

    Memory: 6 GB

    Bus Speed: 800 MHz

    Boot ROM Version: IM71.007A.B03

    SMC Version (system): 1.21f4


    Get Temperature Monitor to see if it's heat related...




    iStat Menus...




    And/or iStat Pro...




    If you have any temps in the 70°C/160°F range, that's likely it.


    Except IntelMacs...