Hitachi Travelstar NVRAM swap

[gtd4242]

Is it possible for the NVRAM chip to be damaged on these drives when a PCB blows? I've successfully swapped these chips when replacing damaged PCB's before, but for some reason I have run into a string of them where the drive will not power up after the NVRAM swap. I don't know if I have lost my touch with these or what, but I have never had so many problems swapping such simple chips. I have the right equipment, and have even swapped the fine pitch Marvel chips on some WD drives, but for some reason I have either run into a string of drives where the chip itself is bad, or I'm screwing up.

[pcimage]

I've had one or two, but not many.

Have managed to fix so far.

[harddrivespecialist]

Bad NVRAM chip can cause it.

[gtd4242]

Is there any way to test these chips?

[rameez]

Check data with eeprom .

[gtd4242]

I don't have an eeprom, but I'm going to figure something out. Do you know where to get one or where I can find information about building one?

As an additional note, I sat down and just practiced for about 4 hours to make sure, as best I can, that it's not something I'm doing. I took a perfectly good working board, I removed and replaced the NVRAM about 15 times. I did this until the board was nearly burned through around the edges. Everytime, aside from once when I was purposfully careless, the board was able to power up the drive.

However, when I placed the chip from one of the dead drives onto that board I was working with, it would not power up. I removed that chip, replaced it with the original, and it worked fine. So I can only assume at this point that something is wrong with the actual NVRAM chips on these drives I've been getting.

[harddrivespecialist]

Your assumption is correct.

[Starling]

Hint: NVRAM version needs to be compatible with ROM version.