SOLUTION: MacBook Pro 2011 15 inch suddenly lost display after PRAM reset

For your MacBook Pro 2011 that lost display after a PRAM reset, it sounds like a common issue related to the graphics card, especially with 2011 models that are known to have faulty discrete graphics (AMD GPU). Here's what you can try to resolve the issue:

Steps to Try:

1. Reset the SMC (System Management Controller):

   • Shut down your MacBook Pro.
   • Connect it to a power source.
   • Hold Shift + Control + Option + Power for about 10 seconds.
   • Release all keys at the same time, then press the power button again to turn on the MacBook.

2. Boot in Safe Mode:

   • Shut down your MacBook.
   • Hold Shift as you press the power button to boot.
   • This will disable certain non-essential system functions and boot using only the integrated graphics.

3. Disable the Discrete GPU: Since the issue could be related to the discrete GPU, you can try disabling it by forcing the MacBook to use the integrated GPU only. You'll need to use a terminal command in Single User Mode:

   • Start the Mac in Single User Mode by holding Command + S during boot.
   • Type the following command to back up the configuration file:

     bash
     Copy code
     mv /Library/Preferences/com.apple.windowserver.plist ~/Documents/
     

   • Reboot and see if it works using the integrated GPU.

4. External Monitor Test:

   • Connect your MacBook to an external display using the appropriate cable (HDMI or Mini DisplayPort).
   • If the external display works, it confirms a problem with the internal display or GPU switching.

5. Reflow or Reball GPU: If the above steps don't work and it's the discrete GPU causing issues, you might need a more hardware-focused solution. A common fix is a reflow or reball of the GPU, which can be done by professionals, though replacing the logic board is sometimes necessary.

Potential Long-term Fix:

If you manage to boot successfully, consider using software like gfxCardStatus to force the system to use the integrated Intel GPU instead of the discrete AMD GPU to avoid further issues.

This issue is well-documented among 2011 MacBook Pros, and Apple's free repair program for this fault has expired. However, the steps above may help you avoid costly repairs.

Let me know if you need further assistance!