I have an older, 2007 15-inch MacBook Pro (model identifier MacBookPro3,1) which has begun freezing repeatedly.

If I boot into Single User Mode it stays operative, however I've begun to get graphic glitches here too:

enter image description here

Booting to the Mountain Lion recovery partition, a disc, or any other graphic interface I get a freezing hang. This is often before the machine has booted completely.

At other times it will repeatedly reboot.

I have reset SMC and PRAM, and run fsck -fy on the drive.

I should also note that the machine generally kicks up its fan pretty quickly and runs very hot, even in Single User Mode, so I am suspecting overheating, perhaps brought on by the video demands?

Does anyone else have a guess at this and/or another diagnostic step?

  • 1
    Also - if you want to upload a picture of the glitches or mention the model year of your Mac in case the RAM / VRAM share the same parts.
    – bmike
    Commented Aug 11, 2013 at 18:07
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    Try using external display to see if it happens there.
    – Ruskes
    Commented Aug 11, 2013 at 18:14

1 Answer 1


The symptoms you describe could all be explained by a failing GPU system but before seeking a hardware repair (or quote), I would try reinstalling a clean version of OS X - perhaps the original version that shipped with that Mac to ensure that the hotness and slowness isn't because of added load the new OS has provided and actually something relating to hardware cooling or heat generation.

Your picture is very telling as well.

The three things that hardware could fail are:

  • LCD panel and cabling
  • GPU itself
  • VRAM

The patterns you show in single user mode could either be software or hardware. If it's hardware, they will get worse over time (perhaps dramatically worse) and we've already covered the software angle. Usually when the hardware is faulty, you can get poor graphics in single user mode or the boot selection screen - so you might be right it's overheating / the hardware starting to fail.

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    Not sure if this is a mid- or late 2007 machine, so it seems original OS could be either Tiger or Leopard. I can attempt a clean install of either of these when I get some time.
    – wxs
    Commented Aug 21, 2013 at 12:33
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    Took it in; it was the GPU. These models had some problems with the unit. Machine is vintage (5+ years old), and a hand me down, so it's to the recycling heap after wiping the drive.
    – wxs
    Commented Aug 30, 2013 at 16:24

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