How to discover what’s stored in your Mac’s NVRAM, how to reset it in Intel Macs, and how you can changes its variables.
There’s no SMC, so you can’t reset it. Although there’s still NVRAM (PRAM), that can’t be reset either: full details of both for M1 models.
How to control whether your 2016 MacBook Pro sounds a startup-chime or start up when you open its case, why you can’t unmute a 2017 iMac, and how High Sierra changes your NVRAM.
Safe mode, or Recovery? Which type of Recovery? How to engage all those useful modes at startup, and when shutting down.
How to enable or mute your Mac’s startup chime, and other neat tricks of the NVRAM.
These store key information for your Mac. Resetting the SMC and NVRAM is no panacea, but can transform an apparently dying Mac.
All the useful key combinations, arranged by function rather than keys.
What to do when your Mac won’t start up, and is acting dead, or at least mortally wounded.
After an interrupted firmware update, my iMac refuses to start up. What can I do?