Friday, March 10, 2017

Fix unable to type password to unlock drive in macOS Recovery Disk Utility

I ran into another unusual problem today, this time working on a 2010 MacBook Pro with OSX Sierra 10.12.  It's been rebooting randomly, and it doesn't appear to be the buggy thermal sensor issue (I pressed down to the right of the trackpad as hard as I could and that didn't short the sensor out).

I tried to run Apple Hardware Test, only to find out that 10.12 was left in a pit by Apple.  It doesn't have Hardware Test anymore, but it doesn't have the newer Diagnostics, either.  Their best suggestion was to run internet recovery (Option-D on startup), but it gives an error - apple.com/support 3034D - which has no documentation.

Why do I always run into problems no one has had before and the manufacturer doesn't document the error code for?

Anyway, I thought we'd start with the hard drive, and Disk Utility found errors.  It's the boot volume of course, so the errors can only be repaired in macOS Recovery.

So we reboot to Recovery (Command-R on startup).

The hard drive shows up in Disk Utility, but the actual system partition isn't mounted at startup, because you need the password.  So I click Mount.  One problem, though.  Keyboard isn't responding.  Not the built in keyboard.  Not an Apple USB keyboard.  Or a PC USB keyboard.  I can toggle Caps Lock, but can't type a password for anything.

So, what do we do when OSX acts stupid?  WE RESET THE NVRAM!

That'd be Option-Command-P-R on startup, and if that's the only thing you learn from this, make it your new Mac goto.  You'll need it alot if you work on Macs that're more than 14 minutes old or have been turned on or taken out of the package.

After that, rebooting to Recovery again produces a working keyboard!