MacBook just bricked itself.

[Ichinisan]

Attempted to install a security update from the App Store. Now, attempting to boot takes several minutes and ends on a screen that says "macOS could not be installed on your computer"

"An error occurred installing macOS. To use Apple Diagnostics to check your Mac hardware, shut down, press the power button, and immediately hold the 'D' key until the diagnostics begins."

"Quit the installer to restart your computer and try again."

"[Restart]"

Clicking the restart button just repeats the same thing.

Holding the D key on boot prompts to connect to WiFi before showing an old (OS9?) style UI. All tests passed.

System information from the Disgnostics:
A1278
MacBookPro8,1
Dual-core Intel Core i5
2.40 GHz
Boot ROM version 83.0.0.0.0
SMC version 1.68f99

The previous time an update bricked my system, it was resolved with a time machine restore or something. How do I trigger that to start?

 

[Ichinisan]

OK...maybe I'm back in business? Used the Apple logo drop-down menu on the failure screen and picked "Startup Disk"

Selected the only disk.

Now it boots normally.

Gonna try the update again...

 

[killster1]

not that i use mac but its cool that you came and told us how to fix if we have same issue. (maybe one day my girl will want a mac lappy)