I have two identical 15" 2012 MBPs.

This Mac has NV RAM, not PRAM but they have the same functionality.

My first thought is how old is that battery? Black screen on boot is one of the classic symptoms. I've replaced the batteries on both mine in the last few months. The ones on Amazon are ok. The battery at OWC is a bit more expensive but it is rated higher and you can get a free return label for recycling.

Resetting the SMC sometimes works; more often it does not.

Reset Launch Services to Default. If there's anything hanging up the boot process, this will fix it. If you have Onyx, it's one of the tools. Otherwise…

1. Open Terminal and run these commands:
2. /System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Support/lsregister -kill -seed -lint -r -f -v -dump -domain local -domain system -domain user -domain network
4. killall Dock
5. sudo mdutil -E /
(enter Admin password when prompted)
6. Restart your Mac

Besides your Mac, this will reset the launch services for each installed app. This fixes a whole lot of problems.


BIAB 2024 Audiophile Mac
24Core/60CoreGPU M2 MacStudioUltra/8TB/192GB Sequoia, M1 MBAir, 2012 MBP
Digital Performer11, LogicPro, Finale27/Dorico/Encore/SmartScorePro64/Notion6 /Overture5