It bricked my mid-2012 MacBook Pro 
On the restart, I got the 'prohibited' symbol, and failed to startup.
Booted to Recovery, disk verify/ repair made no difference.
Reset SMC/ PRAM made no difference.
Luckily I have a time machine backup from yesterday.
On the restart, I got the 'prohibited' symbol, and failed to startup.
Booted to Recovery, disk verify/ repair made no difference.
Reset SMC/ PRAM made no difference.
Luckily I have a time machine backup from yesterday.