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I have a Early 2015 MacBook Pro Retina 13" which suddenly developed a very odd and specific issue earlier today.

When running only the internal display under macOS, the display is unusable - multicoloured garbage and static, moving across the screen. Yet when I hook up an external display the problem disappears and both the internal display and the external one show macOS correctly.

When rebooting and choosing the boot menu with only the internal display, all is well again. When loading macOS, it's fine until about two thirds of the way through the progress bar, and then the static psychedelic freakouts happen again and you can't even see the login screen. Again, hooking up an external display makes both displays work again, until the external one is disconnected (HDMI or Thunderbolt, makes no difference)

When rebooting to Windows 10 Pro under Boot Camp, with just the internal display, everything is fine. If I load from a Gparted Live USB I have, also fine. If I boot a macOS installer, again fine, up until the point a clean install of macOS is performed. It was running Catalina, but I've also tried Big Sur and El Capitan (which is what it shipped with from new I believe). Booting to Recovery from any version of macOS, or Safe Boot, and no issues, perhaps because Metal GPU drivers aren't loading. Not sure.

Having done fairly extensive testing before reaching out here, this leads me to believe it is a software issue with macOS because the internal Retina display clearly works. I'm wondering if it's related to Display Scaling because I usually run it at the "Look like 1440x900" setting and for some reason when booting macOS, the  Apple logo and progress bar are smaller as if the scaling is applied from boot, and that's causing a macOS-only problem.

I've looked for potential Terminal sudo commands I could use to try and force a display driver reset or some such, but have not found any yet.

I've seen display faults on Macs before, but never anything like this. It's incredibly bizarre and specific, not a complete display fault across the entire machine, just macOS when not Safe Booted.

Any advice please? I literally can't work out what the issue is. And I don't want to just use it in Windows 10; it's a Mac, I need it running macOS and it needs to work when not hooked up to another display to get around the issue.

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  • Have you tried deleting /Library/Preferences/com.apple.windowserver.displays.plist
    – sdmeyers
    Commented Apr 10, 2023 at 18:11

2 Answers 2

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I have the same MacBook model and the exact same issue. My current workaround is to use a display emulator (dummy hdmi plug) connected at all times but I am also interested in a better solution. In the iFixit forum (link below), I have been advised that the issue is likely from a faulty logic board, possibly the graphics MUX part. The reason it works in safe mode would be that the integrated GPU is bypassed (same for recovery mode and bootable usb I presume).

https://www.ifixit.com/Answers/View/739408/

That said, I don't understand why the issue disappears on Windows 10 on your side (I haven't tried dual boot so far). I assume Windows 10 should make full use of the integrated GPU as does macos?

One thing I figured is that if I prevent the the following driver to load (AppleIntelBDWGraphics.kext), then I have a functional computer with safe mode graphics.

Update:

Strangely enough, I solved the issue by replacing the screen.

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This is likely due to a hardware issue - When you plug in an external display, it switches the GPU in use, which forces both GPUs to be active (integrated vs discrete). Safe Mode and Windows Boot Camp only use the discrete GPU.

You can try using an app like GfxCardStatus or the link on Apple's site to only use the discrete GPU.

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