I think I figured out how I bricked my 520 SSD. I somehow got an unknown password set in it. There is no way to clear or reset the mystery ATA password in this type of drive so it is dead. I have a lot of experience with hardware drive encryption and have used them many for years. So this was all pretty strange and took a lot of digging to resolve.
I searched the net for others having similar problems and there are a few that apparently did the some thing and lost their ATA password too.
WARNING! - DO NOT TEST THIS THEORY YOURSELF!!
I just want to warn you NOT to do what I did!
1. I was going to simply Secure Erase the drive to replace one version of Linux with another so I wanted a clean disk.
2. I used the usual Partition Magic Boot DVD to erase the drive using the secure erase command. I don't have any computers running Windows anymore so the Intel Windows programs are useless.
3. I turned off the computer, turned it back on, put in the DVD, and the ATA hard drive password prompt comes up.
4. I typed in the ATA password and the computer passed that step and booted off the CD and the tools all came up in Partion Magic. The SSD drive was there all ready to go.
Did you catch the mistake there!? Neither did I... But I NEVER CLEARED THE ATA PASSWORD! Intel's SSD tool box will not secure erase with the password set... But Partition Magic and a whole lot of other disk wiping tools will! They don't care because they will just reset the password to off or "NULL" actually.
5. I performed the secure erase with the option to reset the ATA password to NULL. It took the usual 1 second and reported that it worked just fine with no problems at all.
6. I put in the Linux software loading DVD and hit reboot.
"Reboot" does not ask for the ATA password so I did not notice a problem then.
7. The software loaded to the SSD just fine. I rebooted again and the computer booted off the SSD with the new software installed just fine. I made a few tweeks and updates to the OS no problem at all. It was running off the SSD perfectly.
8. I turned off the computer this time.
9. When I started it again... Now things when all to heck... It asked for the ATA password... Odd... I cleared that when I erased the drive like I had done maybe 50+ times before but with other drives... But I put in the password... WRONG try again.......
I tried every password, default, NULL... But it is none of them. God only knows what secure erasing with an existing password did... But it now has some strange password nobody knows.
I spent a lot of time trying to reset / erase / fix it, but nothing will work as so many of the posts in this forum have told. Once the ATA password is scrambled, the Intel 520 SSD is dead, bricked, useless. Unlike other encrypting hard drives, the 520 locks out with no recovery. Software really can destroy the hardware in this case. Apparently Intel wants it that way...
Only attempt to Secure Erase the Intel 520 SSD with the ATA password ALREADY removed. Apparently people have successfully used other than Intel erase tools to do this. But if the password is set and you try to secure erase it, very very bad things happen. The Intel Toolbox software, very oddly, forces you remove the ATA password first. So there is something going on there.