Case study of NVRAM Repair

First, you need to find the corresponding donor drive.

The requirements of NVRAM compatibility is the following:

a. Same Model

b. Same first two strings of PCB label, like the following picture:

After you find the correct donor, connect the drive to the console box and backup its NVRAM file.

Then specify the NVRAM file as the standard for repair.

Here is a case taking the drive HTS541210H9SA00 as an example. First, it can be detected and we can access data area.

Picture 1 Drive can be detected.

Picture 2 Data area can be accessed

Then I manually edit the NVRAM to make it be undetected and data area can’t be accessed.

Picture 3.The drive can’t be detected because of corrupted NVRAM

Picture 4 Data area can’t be accessed

Now we begin NVRAM repair. I have backup a corresponding NVRAM from donor drive.

First, specify donor NVRAM file

After that we get the following:

Second, the command sequence is “Delay Test”, “Quick Search” or “Search”, as the following:

Delay Test

Search

There will be “ok” message after search finish.

Step —–Click “OK” and “Read NVRAM” to backup the NVRAM. Then switch power off and on, we find the drive can be detected again, but data area is still inaccessible.

Drive can be detected again

Data area is still inaccessible

This is because we have only finished SA Position Parameters repair. We need to proceed to Data Area Adaptive Parameters repair. This time we need to specify the NVRAM we just backup in the former step when Search is finished.