Why is my macbook stuck on boot?

Question

Hard disks

Macbook pro 15 late 2011, SSD in optibe, on which El Capital is installed. Last night it worked fine, but this morning when I turn it on I get a black screen. If you press the keyboard after a minute, a password reset dialog appears. In the recovery mode, the disk sees, but the volume is gray. I had already started installing OS X from scratch, as the installer prompted me to enter a disk password, after which the volume became active, but after rebooting everything is new.
I assume that something is wrong with the boot sector, I tried to find how to disable FileVault without starting the OS, but I did not find anything
PS: people are divided into two types - who makes backups, and who will do them :)

Answer 1

FileVault encrypts all files on the bootable media, and when disabled, a full decryption is performed. So without starting the OS it will not work. If there is no valuable information, you can call the disk utility in the installer and completely clean the media. By deleting the service partition, you will also delete the indication for encryption. And try to put the drive in a regular place for reliability. Then switch back.

Answer 2

Macbook pro 15 late 2011 - ATI discrete graphics card. Judging by the signs, she is dying. https://www.apple.com/ru/support/macbookpro-videoi... - until the end of February of this year, Apple has a free replacement program for motherboards with similar defects.