If NVRAM data is corrupted, the HDD will not be detected or data area can’t be accessed. In such case, we need to repair NVRAM data by HD DOCTOR. Generally, users know how to do NVRAM Repair, but they don’t understand how NVRAM Repair works. Here, I will reveal it to all the users. (Please refer to NVRAM Data Structure in the blog for knowledge preparation).
The difference of NVRAM data from different drives that belongs to same drive family are the addresses of service area data area. And NVRAM Repair is just to repair the two addresses. The diagram below describes the whole procedure of NVRAM Repair.
First, we find a donor drive with same model and same first two strings of PCB identifier on the label. Thus we get donor address.
Second, the program supposes donor address as real address and tries to access service area. If service area can be accessed, the program considers donor address to be the real address. However, if service area is inaccessible, the program jumps to “donor address +n”, where n stands for circulation times from 1 to n.
Third, the program supposes donor address +n as real address and tries to access service area. If service area can be accessed, the program considers donor address +n to be the real address. However, if service area is inaccessible, the program jumps to “donor address -n”, where n stands for circulation times from 1 to n.
Fourth, the program supposes donor address -n as real address and tries to access service area. If service area can be accessed, the program considers donor address -n to be the real address. However, if service area is inaccessible, the program change n to be equal to n+1, and then jumps back to “donor address +n”, where n stands for circulation times from 1 to n.
The program then repeats the third and the fourth step until real address is revealed.
Would you help me to recognize NVRAM chih on the logic board of SEAGATE Barracuda ES.2 500GB HDD model:ST3500320NS.
Thanks in advance