I like these drives usually. If they aren't crashed, you can almost always get the data. But I just ran into one that isn't behaving the usual way. Drive came in with burnt VCM. Client swears absolutely for sure that it has original PCB. Pulled PCB from working same model drive. Put patient nvram on donor PCB. Patient drive would not spin. Removed PCB from heads but still connected to motor and drive spins up. Replaced heads. Now drive spins, heads lift off and drive immediately goes to DRDY, DSC, ERR and ABRT and the drive is not detected and the heads do nothing after the initial short movement. I also find it strange that the 2 PCBs have significantly different VCM and controllers, the failed PCBs sticker starts with 0A29, the controller starts with 0A29 and the VCM starts with 0A29. I've never known these drives to have incompatible donor PCB when they come from same model drive and have nvram swapped. The symptoms are like incorrect or corrupt nvram but is it possible that other components are incompatible.

The preamp have some ID wich can be checked by the FW.
So maybe the correct preamp type needs to be match to the FW.
So you need to match the ROM->NVRAM->PREAMP->SA for correct operation.

Janos

Thanks Janos,
Sounds like I have to get a donor drive with correct preamp. Never had that issue before with these. The drives are a different P/N. Do you think I should try to match model plus P/N, MLC or just as much as possible.

For Hitachi?

I think the "as much as possible" is a good option.

Janos

Habitually, I always check for drive's SN in NVRAM via HEX

_________________
http://pcrecoveryllc.com

Looked at several drives nvram in hex (512 bytes). Don't see anything resembling a s/n.

Turns out, my utility for this drive was messing up. I reinstalled it and was then able to properly access the nvram, reset it and get a full recovery. I hate it when one of my tools messes up and I go in the wrong direction.