Replacing the PCB on a Hitachi 500GB HDT725050VLA380

[Rincewind]

The PCB has died - nasty burning smell.
I'd appreciate some help in getting/fitting a new one.
The drive labeling says
P/N 0A32162
MLC BA2163
Model HDT725959VLA380
Date May 2007

And the PCB label says
0A53043
BA2178
Mda715
H7NN

- What determines a compatible PCB?
- Where can I find one?
- Do I have to do anything else other than swap them over?

Sorry to be so ignorant and thanks in advance for any help

[pcimage]

1. Match first two lines on PCB label
2. Swap NVRAM chip (mandatory)

[Rincewind]

Which one is the NVRAM chip and why must I swop it over?

[pcimage]

Post a good quality photo.

It contains pretty much unique adaptive data, it MUST be transferred.

[fzabkar]

Are there any TVS diodes on your board?

[waqas_ali766]

in hitachi hdd when tvs diode burn, some capacitors and one fet also burn in 2.5inch hitachi hdd.

[fzabkar]

in hitachi hdd when tvs diode burn, some capacitors and one fet also burn in 2.5inch hitachi hdd.

The OP's drive is a Deskstar.

[waqas_ali766]

yes its desk tar. i tell general problem .

[Rincewind]

Hi
Sorry for delayed response - I've been away for w/e.
Picture of board is below - hope that allows you to answer your Qs

[pcimage]

The NVRAM chip is the 8-legged chip, bottom right in your pic.

[fzabkar]

Check D4, D3, and R5 near the Molex power connector.

See http://www.users.on.net/~fzabkar/HDD/TVS_diode_FAQ.html

[Rincewind]

Sorry guys - now I am struggling
D4 is the black thingy above and left of the label D4? That reads open circuit both directions
R5 is just a couple of holes which appear to be connected (< 1 ohm in both directions)
But I cant see a D3 anywhere

[fzabkar]

See attachment.

Attachments

HDT725050VLA380_diodes.jpg (56.83 KiB) Viewed 16624 times

[Rincewind]

BTW if all the disk details are stored on the NVRAM chip, I presume need only a PCB where the first 2 lines on the label are the same. Different size of disc, different part number etc doesn't matter?

[pcimage]

BTW if all the disk details are stored on the NVRAM chip, I presume need only a PCB where the first 2 lines on the label are the same. Different size of disc, different part number etc doesn't matter?

Well not quite accurate as virtually all the "disk details" are on the platters, in the Service Area. But you need the NVRAM info to allow the drive to find those details

But yes, basically you just need to match the 1st two lines and NVRAM transfer. Now, this doesn't ALWAYS work, I've had PCB's with matching 1st two lines with difference ROM versions.

But you should be OK

[lt16]

The NVRAM was added when IBM took Hitachi in '03. The NVRAM stores the number of heads, beginning location of the SA the ROM overlay module checkout and platter adaptive parameter. With these drives the SA location is at a random address. Hence, having the NVRAM chip is requisite. There is a backup of the NVRAM info in the SA-C (unfortunately, this does not exist in ARM family drives).

[BGman]

The NVRAM was added when IBM took Hitachi in '03.

Wow, what a news!!!

[Rincewind]

Well not quite accurate as virtually all the "disk details" are on the platters, in the Service Area. But you need the NVRAM info to allow the drive to find those details

But yes, basically you just need to match the 1st two lines and NVRAM transfer. Now, this doesn't ALWAYS work, I've had PCB's with matching 1st two lines with difference ROM versions.

That's good news - I was having trouble finding a donor drive that matched model number and PCB codes - usually the capacity was different. I think I've spotted a 250GB with the right codes so I'll try that.

[Rincewind]

See attachment.

D3 - Label half under screw so I missed it. Sorry
Open Circuit in one direction
155 ohms in the other

So TVS all OK?

[Rincewind]

Well I finally got round to making the repair.
Apologies to all you out there who have been waiting for news with baited breath !!

I got a donor board; I swapped the 8 leg chip
I plugged everything in and . . . . . . .
The good news was an instant bingley bong as Windows recognised the drive
The bad news was that were no files and Disk Manager told me I had to initialize the disk before Logical Disk Manager can access it.

I then get two options for the "partition style"
MBR
GPT

Seemed safest to do nothing and ask for HELP!!!

TFAI