Hitachi pcb swap

[Solaria]

Hello guys,

The PCB of my HDD fried and now looking for a replacement PCB. I did some research beforehand but getting different solutions from various sites.
One site posted that the two first lines of the PCB has to be exactly the same, while other sites state that even the mechanical harddrive needs to be the same.
Which one is correct?
In which cases does the NVRAM has to be replaced?

Thanks in advance!

[pcimage]

In all cases NVRAM has to be transferred.