6 Replies Latest reply: Dec 28, 2013 6:12 PM by joshpreston
joshpreston Level 1 Level 1 (0 points)

Hey everyone,


I know this has been discussed to death, but I have had trouble finding someone with my exact symptoms, so I thought I'd ask just in case anyone has any insight.


I have a 2007 Macbook Pro with the GeForce 8600m chip. The computer boots up and the gray Apple loading screen illuminates and loads. Then when the screen would normally switch to the desktop, it goes black. I can plug in an external display and the computer works fine. In the "About this mac" window, no internal display shows, just the external. Same with the Displays pane in System Preferences. I try to detect displays but to no avail, only the Cinema display shows up.


So the computer works fine, it just does not recognize the internal display - but I know the display itself works cause it shows the boot screen when I start it up.


I've tried all the PRAM resets and such.


Any ideas?



  • LowLuster Level 6 Level 6 (12,050 points)

    Sorry I have no ideas on what to do or what the specific problem is.


    Have you tried booting the system from an external drive of some type that has a fresh clean install of OS X on it? If you haven't try that. If you have and you get the result then it may be time to put that system out to pasture.

  • Allan Jones Level 7 Level 7 (32,610 points)

    If you can run an external display, that means you likely do not have the dreaded and well-documented Nvidea 8600 failure (I lost my 2007 MBP to it last June). Were it the 8600 problem, an external display would not work.


    Likely causes for your problem are :


    <>broken video cable where it goes through the hinge

    <>failed backlight on the built-in display

    <>failed inverter


    These are fixable for much less that the complete logic board replacement the the Nvdea 8600 failure requires.


    The Nvidea 8600 repair extension program expired just over a year ago:



  • joshpreston Level 1 Level 1 (0 points)

    Thanks Allan! Do you have any resources for looking into how to address/diagnose those other issues you mentioned?

  • Allan Jones Level 7 Level 7 (32,610 points)

    At this point, you have basically diagnosed the issues as far as you can by determining what does and doesn't happen on the external display. If you have your original system disks, one has Apple Hardware Test (AHT). That might pick up a failed inverter but I doubt it picks up a failed backlight or a broken cable.


    I don't know if you can run AHT with an external monitor. The test boots from the DVD so you may not have extensions needed to fire up the external. You can try--just make sure your external is set to "mirrored mode," not "extended desktop," before restarting from the DVD and you have a chance of it working.


    AHT will give you a cryptic code if something fails; post the code and I can try to translate.


    If AHT doesn't further narrow the suspects, you'll need to have it looked at by a pro to get anywhere, unless you are comfortable taking apart something loaded with tiny and delicate electronic bits. If so, tell me your screen size and I can point you to some illustrated maintenance sites.

  • joshpreston Level 1 Level 1 (0 points)

    I do have the disks, I'll dig them out and give it a try and let you know. It is the 15" model, to answer your other question. I'll get back with you after I try the AHT, thanks!

  • joshpreston Level 1 Level 1 (0 points)

    So I ran the AHT and came up with this error:


    4VDC/1/40000003: VideoController


    What do you think?