ST1000LX015-1U7172 more than 1 times unlock the firmware

[KangKung]

Seagate hdd hibrid ST1000LX015-1U7172, 1st firmware unlock
is successfully. Lock again and hdd back to normal.
2nd times unlock, I found the problem, led indicator at terminal
pcb keep blinking while terminal give :

Failed to exchange commands

Flash boot code Digital Signature Verification failure
SEA5 Boot ROM 1.0 (05/05/2014)
Copyright Seagate 2014

Hdd works fine if the firmware I lock again, but in this situation,
does it means I can not do unlock the firmware of ST1000LX015-1U7172 more than 1 times?
This ST1000LX015-1U7172 is for donor hdd.
Thank you for help.

[pepe]

use the original rom image for unlocking, i guess there is a flaw while removing the unlock patch...

[KangKung]

Hi Pepe,

It is happen on two pcs of ST1000LX015-1U7172. Both is working condition, same case can do unlocking for 1 time only.
I am use the modified original rom image (by MRT) for unlocking and use original rom image for locking.
I am agree with you it may be a flaw while removing the unlock patch
Talk to MRT with no reply at all.

[ccc]

This is SSHD drive

Without power off: unlock->Clear the NAND-> write original(unlocked) ROM
Power off then on and you should have hdd in original state.

[KangKung]

Hi ccc...

Unfortunately after 1st unlocking successfully, there is no more 2nd chance to unlocking again as terminal gave :

Failed to exchange commands

Flash boot code Digital Signature Verification failure
SEA5 Boot ROM 1.0 (05/05/2014)
Copyright Seagate 2014

As I said if I lock, SSHD back to normal but no more chance to unlocking.

It is my fault not carried out Clear the NAND in the 1st chance to unlocking?

[pepe]

this situation sounds very strange. It should work just fine if you rewrite the very original rom and start unlocking from there.
very low chance it has anything to do with NAND, i would say 0, coz it complains about boot loader signature...

[ccc]

Hi ccc...

Unfortunately after 1st unlocking successfully, there is no more 2nd chance to unlocking again as terminal gave :

Failed to exchange commands

Flash boot code Digital Signature Verification failure
SEA5 Boot ROM 1.0 (05/05/2014)
Copyright Seagate 2014

I hope, when you try to unlock , that you press "exchange commands(New)" button, not the one that is used for all the other Seagate families....
If you do it correctly and you still have that error, yes, like pepe said, it's strange.....If you write the original Rom everything should be back to normal and you should be able to unlock the Rom like the first time.

[KangKung]

Hi ccc

It have been long time post, but I need to update as closed case, SOLVED.
Yu are right ccc, I miss press the button at the first place, supposed "exchange commands(New)" not just
"exchange commands" .

Everything is goes well and DE works 98%.
Thank you for all .