1 2 3 Previous Next 112 Replies Latest reply: Sep 20, 2012 7:52 AM by Howard Brazee
Howard Brazee Level 1 Level 1 (5 points)

My wife's Mac changed resolutions - possibly as a result of running a full-screen game.   She says it has happened before.   I told her to reboot and let me know if that helped.

 

It didn't, so I went to settings to change its resolution, seeing only 2 options, 1920 x 1200 or 960 x 600.

 

I told her tonight to turn her computer all the way off, meanwhile I would see what I could find out.

 

What should I look at to trace down her problem?


24, Mac OS X (10.7), Home workgroup
  • 1. Re: imac only has 2 resolutions
    X423424X Level 6 Level 6 (14,190 points)

    Try clicking Detect Displays in the Displays preferences.  If that has no effect then try a smc and pram reset.

  • 2. Re: imac only has 2 resolutions
    Howard Brazee Level 1 Level 1 (5 points)

    I already tried Detect displays before my post.     I see now that she doesn't have a "gather windows" button.

     

    I tried the smc by shutting down and unplugging for 15 seconds.   That didn't do anything. 

     

    Then I shut down then pushed the on button and held command-option-p-r down.   I got the white screen 4 times before I guessed I needed to let go of the keyboard.    No change.

     

    Did I do something wrong, or is there another problem?

  • 3. Re: imac only has 2 resolutions
    Howard Brazee Level 1 Level 1 (5 points)

    I tried to answer this, but appeared to quote and say "This solved my problem".   It didn't.    Sorry about my confusion.

  • 4. Re: imac only has 2 resolutions
    X423424X Level 6 Level 6 (14,190 points)

    If it didn't work I don't know why you flagged my suggestion as correct.

     

    I wouldn't expect you have a Gather Windows button if there is only one monitor, i.e., your iMac.  Also there shouldn't be an Arrangement tab either.

     

    The cmd-opt-p-r sequence, liek all the boot key sequences should be pressed immediately after the boot chime.  The machine will reboot again shortly after that.  You can stop pressing the keys when it shuts down to start that second reboot (this is explained in the pram reset link I gave you).  If this sequence of two boots did not occur you didn't do the pram reset correctly.

  • 5. Re: imac only has 2 resolutions
    Howard Brazee Level 1 Level 1 (5 points)

    This time I only got the 2 boots, waiting to hear the chord then letting go as you instructed.

     

    Same result though.

  • 6. Re: imac only has 2 resolutions
    X423424X Level 6 Level 6 (14,190 points)

    Just to make sure, we are only talking about an imac with no other connected monitors here, right?

     

    See what happens if you boot in safe mode (shift key after boot chime).

  • 7. Re: imac only has 2 resolutions
    Howard Brazee Level 1 Level 1 (5 points)

    Yes, it is just an iMac with no other monitors.

     

    Safe mode didn't change anything.

  • 8. Re: imac only has 2 resolutions
    Howard Brazee Level 1 Level 1 (5 points)

    The game she was running when the problem started is Acropolis

  • 9. Re: imac only has 2 resolutions
    X423424X Level 6 Level 6 (14,190 points)

    So smc and pram reset has no effect.

     

    Safe boot has no effect.

     

    I'm inclined to think it has nothing to do with that game and this failure is just a coincidence.

     

    The only thing left I can suggest it run Apple Hardware Test.  If the screen doesn't have or allow you to set the resolution when booted into AHT then it's time to take to apple for repair.  I think your video card may have failed.

     

    Intel-based Macs: Using Apple Hardware Test

     

    OS X Lion: Use Apple Hardware Test

  • 10. Re: imac only has 2 resolutions
    Howard Brazee Level 1 Level 1 (5 points)

    I'll set up an appointment at the Apple Store.   She's on her 2nd video card (and her second hard drive).   I wonder what kills her video cards.

     

    I'll let you know what they say.

  • 11. Re: imac only has 2 resolutions
    Howard Brazee Level 1 Level 1 (5 points)

    The genius did two things I should have thought about:

    1.   Boot to an external drive - this showed all of the expected resolutions, indicating a software, not hardware error.

    2.   Ran a permissions repair.

     

    While the permissions repair was being run, she checked databases and discovered that this problem gets fixed by reinstalling Lion.

     

    So I went home and prepared to reinstall Lion.    In a couple of days her computer room will be painted and re-carpeted.   So I set it up in the basement, tested the access to the Internet, and rebooted with my OSX memory card pluged in (pressing option).    I started to run Recover, but my computer says it needs to be connected to the Internet.    I could not find anything to set up from this boot, so I will take the computer upstairs and plug the Ethernet cable in it and try again.

     

    Meanwhile, how do I fix it so that next time I don't need the Ethernet cable?

  • 12. Re: imac only has 2 resolutions
    X423424X Level 6 Level 6 (14,190 points)

    The genius did two things I should have thought about:

    1.   Boot to an external drive - this showed all of the expected resolutions, indicating a software, not hardware error.

    2.   Ran a permissions repair.

     

    So after that did your system show the proper resolutions when you boot from it?  I ask because if it did it would be one of the few instances I've heard of where repair permissions actually fixed something!  Or...

     

    While the permissions repair was being run, she checked databases and discovered that this problem gets fixed by reinstalling Lion.

     

    ...is this the "solution" the "genius" came up with because you still didn't get all the resolutions after the repair permissions?

     

    So I went home and prepared to reinstall Lion.    In a couple of days her computer room will be painted and re-carpeted.   So I set it up in the basement, tested the access to the Internet, and rebooted with my OSX memory card pluged in (pressing option).    I started to run Recover, but my computer says it needs to be connected to the Internet.    I could not find anything to set up from this boot, so I will take the computer upstairs and plug the Ethernet cable in it and try again.

     

    Meanwhile, how do I fix it so that next time I don't need the Ethernet cable?

     

    Without an installer disk (or flash drive) I think you must have an internet connection to reinstall Lion.

  • 13. Re: imac only has 2 resolutions
    MelvinMoo Level 1 Level 1 (15 points)

    I have same issue. It occurred after installing 10.7.4 .... So I imagine that you updated the os and then noticed the problem. Reinstalling Lion did not fix this for me. In fact I reinstalled about 3 or 4 times. There is a defect opened on this. I think it is only affecting older iMacs. Mine is an older 24 inch 2006 model. 

  • 14. Re: imac only has 2 resolutions
    JazzmanJohn Level 1 Level 1 (5 points)

    I have a 2007 iMac and, after today's Lion update, it did the same thing. Is there a fix?

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