I have a hitachi HDS721010CLA332 1tb drive that stopped working. It was not detected by windows 7 at all; the BIOS did not display it either.

I had another hitachi drive of the exact same specs and swopped the boards, and the drive was detected in BIOS and in Windows. But in Windows it only showed up in the drive management screen, and said it was uninitialized. I haven't initialized it yet, but I suspect once I do no files will be seen.

Can I know if this business about swopping Nvram on the boards also applies for the Hitachi HDS721010CLA332? Even if both donor and receipient boards have the same specs and firmware (3EA) already?

Where is the nvram chip anyway?

you need to move the NVram over. Post a pic and we can show you the ROM information. But I have a feeling the problem is somewhere else. Very rarely I have seen this family have board issues.

What makes you think it is a PCB problem?

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Hard Disk Drive (HDD), Solid State Drive (SSD, SATA, NVMe, etc), USB Flash Drive and RAID Data Recovery Specialist in Massachusetts

Here is a pic.

Because with the original PCB, the PC just got stuck at the bootup POST. in the BIOS the drive wasn't detected and shown as a possible boot drive.

After I swopped the PCB with another one, these worked, just that I can't see the data.

Does the drive spin with the original PCB on? Furthermore, why do you think it failed? Did you notice something happen prior to failure?

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Hard Disk Drive (HDD), Solid State Drive (SSD, SATA, NVMe, etc), USB Flash Drive and RAID Data Recovery Specialist in Massachusetts

How can i test if the drive spins without opening it? Anyway the failure to spin up was intermittent until recently. Usually whenever I failed I rebooted 2-3 times and it worked but now that doesn't solve it anymore.

Through listening and touch. You will hear internal components gently making sounds. Also it emits a slight vibration.
These should indicate spinning.

Yeah, if it worked once every 2-3 reboots, then more than likely it is not a PCB issue. Likely the problem is firmware and/or mechanical related. Problem is, all these rebooting attempts really have been exposing the disks to further damage. Not good.

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Hard Disk Drive (HDD), Solid State Drive (SSD, SATA, NVMe, etc), USB Flash Drive and RAID Data Recovery Specialist in Massachusetts

Okay, i tried again. I have no idea if it's spinning up with either pcb installed.

but with the original pcb, i get stuch at the bootup screen and windows doesn't even load. Bios cannot find the drive at all.
Without any way to access the drive I can't investigate further.

Swopped the pcb alone, without the nvram, and I can boot into windows. Using a hard drive utility to view the uninitialized drive gives strange results. Other drives return things like [SEAGATE, 4TB], while this drive returns [ , ]. Like it cannot see the drive firmware.

Right, it makes sense, because, as is, the donor PCB is not fully compatible with your drive.
By the way, swapping PCBs on Hitachi drives like that could in theory cause further firmware damage. rarely, but sometimes it could happen. It has to do with how Hitachi designed their drives with regard to firmware. Should test only by ensuring firmware is compatible through methods already suggested in previous posts with regard to NV-RAM or by ensuring firmware does not actually get activated while testing.

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Hard Disk Drive (HDD), Solid State Drive (SSD, SATA, NVMe, etc), USB Flash Drive and RAID Data Recovery Specialist in Massachusetts

Both are using the same 3EA firmware. Is the nvram the same as firmware?

NV-RAM is a firmware component. Firmware is made of several components.

_________________
Hard Disk Drive (HDD), Solid State Drive (SSD, SATA, NVMe, etc), USB Flash Drive and RAID Data Recovery Specialist in Massachusetts

Sounds to me as if the original HDD's BIOS ROM would have to be "swopped" as well

is there any way to backup the rom before transplanting?

yes, using a programmer

Can I know for this hitachi drive, when is the NVram with the head info written to? Is it only at the factory, or is it done whenever you format the drive?


reason is because I have another drive of the same firmware version, model number and batch number. I was wondering if this pcb swop would work, or do I really need to swop the nvram chip?

yes

no

you really have to swap the NVRAM (or it's content)