A couple weeks back, my wife asked me to take a look at her Macbook Pro as the display was scrambled with black and white shapes. After rebooting the laptop a couple times, the shapes disappeared and the Apple logo was shown with the spinning circle, but the OS was never loaded. After several failed attempts, I thought the hard drive might have died so I ordered a new one and installed it myself since the laptop was no longer under warranty. Besides a couple problems with the OS installation after the drive had been replaced, the laptop appeared to be working great.
The other day, my wife called me over again experiencing a new problem. Upon rebooting the laptop the default OS chimes were heard through the speakers, but the display remained black and the laptop kept rebooting. This time, I decided to reset the PRAM by pressing Apple+Option+p+r while powering on the laptop. This fixed the constant rebooting, by the display was scrambled with black and white shapes. While the display was not always the same, the best way to describe it was like a piano keyboard with the keys going horizontally on the screen, but also with vertical columns of mostly black with white speckles in them.
Initial Google searches for this problem turned up very little. Because the laptop was no longer under warranty, I figured it was probably hosed. After much searching, I came across the following Apple KB article from the Mac forums: http://support.apple.com/kb/TS2377. While I could not be sure, this sounded very similar to the issue. On a whim, I brought the laptop over to the Genius Bar (make sure to have a reservation: http://concierge.apple.com/store/R250) hoping for a miracle. The technician ran a GPT test on the laptop and reported that the NVIDIA card had in fact died. The bad news was the laptop repair took three days, but the good news was it did not cost a thing! My hope is that this entry will make it easier for people to find this solution if they are experiencing the same problem.
© 2010, Steve Flanders. All rights reserved.