Page 1 of 1

T420 acting weird

Posted: Thu Dec 27, 2012 2:20 am
by mikemex
Hi guys,

I just seen the first blue screen in many years and I'm thinking it's hardware related. I recently added an mSATA drive to my machine. It's a MZMPA128HMFU (Samsung PM800) with firmware AXM18H1Q. I bought it on sale on eBay for about $90 but it was new. I know drives fail but I didn't know they can crash the system when they do... I was on the idea that RAM was more likely to be the cause.

Anyway, the SSD was working perfectly until I decided to add a password to it. Now when I restart the machine it passes all security except for the password for that drive. It asks for it but it doesn't allow me to enter it. It fails three times and the machine locks.

It's weird because on a cold boot the master password passes security for both drives just fine. And the drive itself seems to be running fine; except for that lock up I've noticed no issues.

I was wondering what's your opinion about this...

UPDATE:

1) I've had no issues whatsoever with the hard drive. It seems like there is a problem with the sound driver which caused the crash. I was playing music when it happened. Most likely 64 bit drivers aren't as polished as 32 bit ones.

2) The password issue seems to be a bug in the BIOS, my X220 does exactly the same. The switch over UEFI seems to have caused lots of issues. I've seen the BIOS change log and they are having a lot of trouble getting it to work properly after suspension and seems like there are issues with rebooting the machine too. How do I report this to technical support?

Re: T420 acting weird

Posted: Sun Dec 30, 2012 7:46 pm
by richk
The password problem sounds like a bug in the concept, because if it works as I expect, I wouldn't know how to correct it. I'm sorry, but I don't know for certain how the password on the mSATA drive is hashed, but I would expect it works the same as a regular HDD. I won't go deeply into the process, but I will say that the regular HDD password is hashed differently from the POP and SVP. On a cold boot, if the POP and HDD (text) passwords are the same, the BIOS will calculate both hashes and unlock the machine and the drive, even though the hash stored on the drive is different from the hash stored for the POP/SVP. The drive hash isn't stored anywhere, not even in memory, after it is used to unlock the drive. It is only on the drive, and in a place that cannot be read, only challanged. If the password used for the challange, the drive is unlocked. A restart is different in that the regular HDD is never reset to require the password to be reentered. My guess is that the mSATA drive gets reset so that it needs the hashed PW and it isn't available anywhere, other than on the drive.

Re: T420 acting weird

Posted: Mon Dec 31, 2012 3:44 am
by mikemex
richk wrote:The password problem sounds like a bug in the concept, because if it works as I expect, I wouldn't know how to correct it. I'm sorry, but I don't know for certain how the password on the mSATA drive is hashed, but I would expect it works the same as a regular HDD. I won't go deeply into the process, but I will say that the regular HDD password is hashed differently from the POP and SVP. On a cold boot, if the POP and HDD (text) passwords are the same, the BIOS will calculate both hashes and unlock the machine and the drive, even though the hash stored on the drive is different from the hash stored for the POP/SVP. The drive hash isn't stored anywhere, not even in memory, after it is used to unlock the drive. It is only on the drive, and in a place that cannot be read, only challanged. If the password used for the challange, the drive is unlocked. A restart is different in that the regular HDD is never reset to require the password to be reentered. My guess is that the mSATA drive gets reset so that it needs the hashed PW and it isn't available anywhere, other than on the drive.
I found this. Apparently the BIOS is locking the drive so it won't respond unless you turn it off.

Again, how do I report this to Lenovo?

Re: T420 acting weird

Posted: Fri Apr 12, 2013 12:36 am
by mikemex
I still have the issue with the updated BIOS. I can't believe I'm the only one experiencing this bug...