Sign in with
Sign up | Sign in
Your question
Closed

What is underlined in bar code pcb hard drive

Tags:
  • Hard Drives
  • Western Digital
  • Storage
Last response: in Storage
Share
November 11, 2012 7:21:03 PM

I have a western digital hard drive and was wondering what's the underlined stuff on the bar code sticker, I know the previous letters and numbers indicate the model. Please help.

More about : underlined bar code pcb hard drive

a c 336 G Storage
November 11, 2012 7:48:45 PM

Can you be more specific?
Score
0
a c 101 G Storage
November 11, 2012 7:54:35 PM

does it matter?
Score
0
Related resources
a c 336 G Storage
November 11, 2012 7:57:18 PM

maybe
Score
0
a c 101 G Storage
November 11, 2012 8:07:42 PM

fzabkar said:
maybe

sorry, that was for ramyzenda
Score
0
November 11, 2012 8:13:04 PM

Thanks alot for your reply..
Well on the hard drive PCB there's a sticker with a bar code that indicates the model of the PCB next to it is another code that's under lined. what's that about.
Score
0
November 11, 2012 8:16:10 PM

Yes I guess it matters, I need to know is it a serial number of some sort that makes that PCB unique to my drive, or I will be able to find one that's exactly similar on another hard drive.
Thanks..
Score
0
a c 336 G Storage
November 11, 2012 8:18:23 PM

The PCB has a part number. The model number of the drive is on the label on the cover.

Are you referring to the 2061-xxxxxx number?

EXACTLY which numbers are you referring to? Give us an actual example.

Score
0
a c 336 G Storage
November 11, 2012 8:22:51 PM

Merely matching the PCB part number is usually not enough for WD drives. It is not the serial number that makes your PCB unique.

Most modern HDDs store unique, drive specific "adaptive" information in a serial EEPROM chip. This chip, or its contents, needs to be transferred from patient to donor. In WD drives, this chip is usually located at U12.

The following PCB suppliers offer a firmware transfer service, either for free, or for US$10:

http://www.donordrives.com
http://www.onepcbsolution.com
http://www.hdd-parts.com

I would advise that you avoid those suppliers who don't tell you that a board won't work without modification. Often they will attempt to obscure the requirement for a firmware transfer by deceptively describing their products as being "for data recovery only".

Alternatively, if you are not adept at soldering, your local TV/AV repair shop should be able to transfer the chip for you.

Onepcbsolution.com also offer a firmware transfer service for US$20 if you have purchased your board from a different supplier:

http://onepcbsolution.com/firmware-xfer-without-pcb.htm...

Some PCBs do not have a discrete serial flash memory chip. Instead they store the adaptive data inside the Marvell MCU (the largest chip). In this case you will need a "PCB adaptation" service.

The following PCB supplier includes such a service for free:
http://www.donordrives.com/services
Score
0
November 11, 2012 8:51:28 PM

Thanks a lot fzabkar that was a lot helpful. here's my example:
2061 701590-l00 01p XC xxxx xxxx x xxxxxxx xxxx
the underlined code is what's after XC to the end.
Please note that I replaced the real code with xs as I don't know what that code stands for, is that the part number you where refering to ?
Score
0
a c 336 G Storage
November 11, 2012 9:02:09 PM

Your PCB is one of those where location U12 below the Marvell MCU (big "M") is vacant:

http://pcb-hdd.com/images/WD6400AAKS-22A7B2%202060-7015...

Therefore you will require a "PCB adaptation service". In the event that the "adaptives" cannot be retrieved from your dead board, then a backup copy, if its exists, will need to be recovered from the hidden System Area on the platters.

General rules for donor matching are here:
http://www.donordrives.com/blog/pcbswapguide
http://www.donordrives.com/hard-drive-pcb-donor-swap-ma...

That said, depending on the fault, sometimes there is an easy, no-cost DIY fix. What are the symptoms?
Score
0
November 11, 2012 9:20:43 PM

Thanks.. It doesn't start or spin or anything. That happened after I connected it to electricity using an external SATA to USB connector. I heard a tiny bang near the plug and then the connector died, well I don't care of coarse considering what happened to the drive. I went to this electronics guy who exchanged the PCB with another one and did some software voodoo (but he did not connect the old PCB, as I can recall) and then it started and I found my data. relieved as I was, still I was reluctant to buy it since the code on the board doesn't exactly match his own, I was concerned that it might damage any of the interior parts of the hard drive and make the problem worse, since the data is very important to me. so I switched back, and waited for professionals' opinion. Still I'm curious what does the rest of the code mean?
Score
0
a c 336 G Storage
November 11, 2012 9:49:35 PM

You were lucky. The data recovery professionals give you only a 5% chance that a straight board swap will work. It appears that the donor's and patient's adaptives are in close tolerance.

As for the actual problem, it appears that one or both of the +12V or +5V supplies were overvolted. If you have a multimeter, measure these 4 components:

http://www.users.on.net/~fzabkar/HDD/bigcircuitboard_di...

There will most probably be a shorted TVS diode and an open circuit zero-ohm resistor. If there is no other damage, then the fix is a simple one.

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

Depending on the severity of the overvoltage, you may also have a damaged motor controller chip ("SMOOTH").

As for the codes, I don't know what the trailing numbers mean. In any case the important ones are the first three groups, ie 2061-701590-l00 or the equivalent 2060 number on the PCB artwork.
Score
0
November 11, 2012 10:12:57 PM

Thanks greatly for your help..
So as I figured out, of what u posted is that if the first three groups match, that's enough to confirm PCB compatibility, I guess that his board matches my first 2 groups. So do you think I should go with the board. And what do you mean that a 5% chance that a straight board swap will work.. Is my data in danger here ? or was there any damage caused to any internal part?
Shouldn't the TVS sacrifice it self in order that no more damage goes through ? Considering another symptom that a slight amount of heat is generated near the power source on the board when connected after the damage..
Score
0

Best solution

a c 336 G Storage
November 12, 2012 3:50:36 AM

The PCB and HDA (Head/Disc Assembly) are calibrated as a unit at the factory. The calibration data are stored in the flash memory on the PCB. Each head has different physical characteristics such as frequency response, amplification, separation between read and write elements. HDD manufacturers tune each head for maximum performance and minimum error rate. They also try to maximise data density by implementing Variable Bits Per Inch (VBPI) and Variable Tracks Per Inch (VTPI).

See http://hddscan.com/doc/HDD_Tracks_and_Zones.html

When a drive powers up, it tries to load its firmware from the hidden System Area (SA) on the platters. In order to find the SA, the drive needs to consult the adaptives in flash memory. If foreign adaptives are used, and if they are not in close tolerance with the original ones, then the drive will not be able to locate the SA. Instead it will click for a while and then fail to correctly identify itself.

If the drive does in fact manage to read the SA, then you may still not have complete, error free access to your data. There may be one or more heads that will be difficult to read, or there may be certain zones that are inaccessible. In such cases there is the risk that the drive will deem a sector to be bad, and then try to replace it with a spare. This means that the spare sector will be written in a slightly different location. The grown defect list (G-List) will also be updated. If there are too many new defects, then the G-list may overflow, resulting in worse problems.

So to answer your question, you won't do any physical damage by trying a replacement board. If it doesn't work, it will just click and give up.

As for the TVS diode, if the associated resistor has gone open circuit, then the board will probably have other damage. I won't be able to tell you any more until you measure something.
Share
November 12, 2012 4:59:50 AM

Thanks a lot for your well informed reply. It was greatly educational..
So I won't do any physical damage, and I guess electrical damage as well, so what about the data (which I don't have any back up of)? You said something about bad sectors..
The fact is I don't have any experience handling electrical tools, though I slightly understand how it works. So I will retreat a little bit in that area..
Do you have any advise regarding the board I found at the shop, and is there a way to confirm that all of my disk is accessible, just after the board is installed and not later when any long term damage has took place?
Score
0
November 12, 2012 1:24:36 PM

Best answer selected by ramyzenda.
Score
0
November 12, 2012 1:37:58 PM

fzabkar can you provide any help ?
Score
0
a c 336 G Storage
November 13, 2012 5:51:39 PM

I wouldn't trust your drive with foreign "adaptives" for the reasons I have outlined. Watch the SMART data. If the Reallocated Sector Count begins to rise, or if the Raw Read Error Rate and other error rates begin to increase, then this will tend to confirm that the boards are not perfectly matched.

At the very least, backup your critical data. Afterwards you might try to repair your original board.
Score
0
November 14, 2012 1:41:43 AM

Thanks a lot for your reply..
Where can I watch SMART data? Can a tool like everest do the job?
And what are the correct numbers to compare to?
Please advice....
Score
0
November 15, 2012 8:38:39 AM

I've used everest to get SMART data today. I avoided using the hard drive as much as I could, fearing I'd lose any data as I don't know if it would mess it self up. I don't even know if it would be safe to copy that data and if it would land safely and correctly on my other drive since it possibly won't read things correctly or mess the data in the way (Am I accurate?). I also found something really weird, I compared my drive sizes with screen shots of the same thing which I took when I've just repaired the drive. I found that all of them has added up exactly 8192 bytes each.. I've just re-installed AVG antivirus which adds a file to each drive, or the recycle bin, so out of good faith I'd assume maybe it's the cause... Here are the results from everest:

http://postimage.org/image/42laf3sml/

Please my friend tell me what to do..
Score
0
November 17, 2012 2:37:47 AM

Please fzabkar tell me if it would be safe to access the drive and/or copy the data... And if you can explain what happened, and my drive's condition..
Score
0
!