Vertical stripes at booting. GPU fail MacBook 13" unibody, 2011

Dan,

Thank you for your prompt reply.

I could not post a picture. However, the following link shows a picture of a screen identical to the one appearing in my macbook:

https://discussions.apple.com/thread/255...

@pabjim - Are you sure your system is a 13' not the larger 15 or 17" models? The image shown is typical of the AMD dedicated GPU failure of the 15 & 17" models not the 13" series.

Can you give us some background when the system started to exhibit this problem. A picture would still be helpful. If you are struggling posting it here. Just create an answer and within the text box is a menu offing formatting options to far right is the image toolbox clip on it to then add your images, then click on them to post the tag into the text where you want to place it.

You are absolutely right.

This are the specifications of my laptop

MacBook Pro (15-inch, Late 2011)

Serial Number: C02HG9PADV7L

Purchased on May 12, 2012.

I cannot turn it on and take a picture if it, but the image in the link I posted is identical to the one in my MacBook -that is, only the vertical blueish stripes without the Apple logo.

I had the same issue about a year before. I found a fix online in which you disable one of the graphic processors using the command prompt. It worked fine but I forgot that after you do that is not advisable to do a NVRAM/PRAM reset. I did the reset by accident, and I got the stripes screen again. I tried everything I did the first time I had the same issue, but nothing worked

I was planning to dispose of it or donate it to someone that could repair it. Thus, I removed the hard drive and the battery. But I changed my mind and decided to repair it myself.

@pabjim - OK now it makes sense! I've altered your model info so it's now correct.

Yes, the 2011 15 & 17 models has a lot of dedicated GPU issues which you have already discovered. The setting you had used disabled the AMD chip and only allowed the Intel graphics engine to work. And as the chip has failed it often times won't let POST to pass locking the system up as well.

So getting back to your question, replacing the logic board might be iffy as the replacement will be a used board which could also have a bad AMD chip. Some people found reheating the whole logic board can fix things I'm not sure if that's a good idea as you risk killing it altogether. The idea was to cause the Tin whiskers to recede that are creating a short within the chip. I prefer the direct heat via a hot air system onto the chip after warming the logic board with a preheater using a method of controlling the heating and cooling of the board.

(Cont)

What you had likely used was this great tool gfxCardStatus to get it working. As your system in this locked state will require getting in to Safe mode to the copy off the tool from a thumb drive or what ever media you can physically shuttle the file from your other system.

But to get to Safe mode you need to unlock SMC first. Here we want to carefully disconnect the battery and then with nothing connected for cords into any of the ports. Press and hold the power button to fully discharge the logic board.

Now the tricky part! You'll need to connect the MagSafe and as soon as you do the system will spontaneously restart! Which is good but we need to quickly enable the startup command Shift Key via the keyboard as soon as you hear it startup. Your system should now be working off of the integrated Graphic engine within the Intel chip. If not that's a deeper issue.

Reference: Start up your Mac in safe mode