MacBook Pro Has Vertical Stripes on Sign-In Screen & Won’t Log In; Simply Keeps Restarting

These hobbyist hacks may return your computer to servicablity:

Install gfxCardStatus (https://gfx.io) and set it to "i" (integrated graphics only). It will allow your MBP to run on integrated graphics only, bypassing the discrete GPU which has the issues. This may allow your MBP to run normally, although it will have reduced graphics performance when permforming demanding graphics tasks. The alternative is replacing the logic board, which is not cost effective on a machine that old, unless gfx does not resolve the issue and you really want to keep this MBP.

There is an acknowledged bug in the current version of Cody Kreiger's Open-Source gfxcardstatus, and the developer has confessed he does not have time to fix it right now.

There is a fork off the main build by steveschow available that seems to fix that problem for current versions of MacOS such as ElCapitan and Sierra. He provides a finished .app for direct download -- you do not have to compile anything.

https://github.com/steveschow/gfxCardStatus/releases

Also note that if your Mac does not run long enough to allow gfxcardstatus to be added, this is not really practical.

In addition, Steve Schow writes that he has abandoned further development -- because there are better solutions available [for both the 2010 model and 2011 models]. In particular, the use of ArchLinux bootable CD to gain access to and re-write the EFI on the drive, and permanently disable the discrete graphics chip. This page and scroll down past the list to the blog:

https://github.com/steveschow/gfxCardStatus/

there are two similar procedure listed. I used the second from MacRumors as it seemed easier. I have made the Arch Linux bootable CD on another Mac, and tried this approach. I now have a perfectly-functioning MacBook Pro late 2011 15-in model with Discrete Graphics disabled. Runs just fine.

Try an NVRAM reset:

How to reset NVRAM or PRAM on your Mac - Apple Support

On that Mac, the nominal 2.5-in form factor drive can easily be removed and placed in an external enclosure, used with a non-enclosure adapter, or even with a "toaster" style drive holder to get USB or Firewire or ThunderBolt access to the drive data.

That MacBook Pro has dual graphics:

the Discrete Graphics chip, used for intensive operations, has 1 GB of private Display RAM.

the Integrated graphics chip, used for more mundane operations, shares a portion of main memory.

In this case, stripes and distorted colors on the screen while doing ordinary operations may indicate a RAM Memory problem.

Unfortunately, it won’t even let me get past the log-in screen to add any of these.

Mine did that as well. I tried removing the drive and using another mac to add that little utility to the drive, but that did not solve the problem.

I ended up making a bootable Linux CD and Patching the EFI file with it, as described in some of Steve Schow's postings. That worked very well, and my MacBook Pro early 2011 is serviceable again.

The Apple store no longer has parts, so they will resist servicing your Mac.

But they can tell you whether the Discrete graphics processor has failed by running the 15-minutes long Video Switching Test (VST). I am told if it fails, it fails very quickly, and only goes the full 15 minutes if is passes.

what model MacBook pro, by year and screen size?

Hi morobbb,

Based on the details that you’ve provided, FileVault is on, and your Mac is either attempting an update or a reinstallation. What I can’t explain, though, is why stripes are appearing on the login window.

If you want to test your Mac’s hardware, please see this article: https://support.apple.com/en-ca/HT202731

To reinstall the operating system (macOS, please see this article: https://support.apple.com/en-ca/HT204904 Doing this should resolve the issue, and you won’t lose any data unless you choose to erase your startup disk.