If your mac is using a firmware password the lock icon appears when you try to start up from another disk or volume such as an external drive or macos recovery enter the firmware password to continue.
Macbook no entry sign on boot.
29 2010 10 33 a m.
I recommend don t change the hard disk right away without checking hard disk you have now.
Mac os x has several bootup symbols including a universal prohibitory sign that indicates critical files are missing from the boot volume.
Either the system on the hard drive has been corrupted and it can t boot from it or the hard drive itself is damaged.
I created a bootable usb using disk creator and attempted to boot from it so i can load the os onto the new drive.
But i keep seeing the no entry icon.
Model a1502 2 4 2 6 or 2 8 ghz dual core intel processor released october 2013.
Managing a prohibitory sign at os x bootup.
This means one of two things.
Thanks for the a2a.
How to fix no entry sign on mac factory reset.
You don t say how old your macbook pro is so that could also be a factor.