The display on my 2012 Macbook Pro Retina (10,1 with 2.6 GHz i7) suddenly stopped working. It still turns on (startup sound, keyboard backlight) and I was able to enable remote access for diagnostics and double-checking that all files are recovered. I'm fully prepared for the machine to be toast, but if I could continue to use it in some capacity that would be nice. Perhaps the integrated graphics are still working and need to be switched on somehow. I have tried a full set of resets, including bringing it into an Apple store. (They could only do resets at the Apple store, as they wouldn't open it due to its age. It takes a while to turn on, so it wasn't clearly on for their diagnostics.)
It looks like the discrete GPU (GT 650M) is the problem, because it is no longer even showing up the output of system_profiler:
Graphics/Displays: Intel HD Graphics 4000: Chipset Model: Intel HD Graphics 4000 Type: GPU Bus: Built-In VRAM (Dynamic, Max): 1536 MB Vendor: Intel Device ID: 0x0166 Revision ID: 0x0009 Automatic Graphics Switching: Supported gMux Version: 3.2.19 [3.2.8] Metal: Supported, feature set macOS GPUFamily1 v4 Hardware: ...
It looks like there are some similar issues (How to disable discrete graphics card and use only integrated graphics MacBook Pro Early 2011?, MacBook Pro: How to disable discrete GPU permanently from EFI?), but none of those mention the display itself not working. In an attempt to switch (at least temporarily) to the integrated GPU, I tried:
sudo pmset -a gpuswitch 0
based on 2015 MBP - how to force integrated graphics?, but that did not work. Generally, I'm looking for advice or next steps. Specifically:
How can I determine what has happened to the dGPU, and whether there are any other problems? I cannot see the screen (obviously), but I can SSH in and see the output of
If the dGPU is toast, why aren't the integrated graphics working? I tried plugging an external display into the HDMI port to no avail, would a thunderbolt display be tied to the integraded graphics?
Are there any logs I can look at to see on (say) startup what's going on? If there are any onscreen error messages, I can't see them.
I'm happy to perform whatever diagnostics I can and report on them here.