TideLog Archive for May, 2012

As I mentioned in the last post, a lot of so called data recovery engineers like fzabkar on HDDGuru forums will claim that the DCM of a Western Digital drive, and the serial number must match as well as the model/firmware MDL number when doing a board swap. This is NOT true. Here I’ll show you just exactly what has to match on a Western Digital.

As an example I’ll note down the details of my company laptop’s new 500GB WD drive. On the label are the following sets of numbers:

MDL: WD5000BPVT – 00HXZT1 – This is the combined Model and Firmware numbers, this is the MOST IMPORTANT, these are really the ONLY set that MUST match.

S/N: WXM1xxxxED69 – This is the Serial number, which is UNIQUE TO EVERY drive, so you will NEVER EVER find a board with matching one. Every product in the world has its own personal unique number, just like humans have unique fingerprint patterns, so this is irrelevant if you’re seeking a donor board. I’ve replaced some characters in my serial here with x’es to anonymise it.

WWN:50014EE206116170 – This is a World Wide Name number which is the unique manufacturer identity.

DATE: 18 MAR 2012 R – This is the manufacture date. An R next to it means Recertified, it will also have Recertified written on the right of the big bold capacity marking on the top left of the sticker, as my drive is recertified. This DOES NOT have to match on a donor, the recertified status is irrelevant, it simply means that Western Digital have re-checked it as a customer return and recertified it as new, reprinting the label to show this.

DCM: EBOTJBB – This is the Drive Configuration Matrix string, which identifies the configuration of the drive, such as type of motor, number of platters, heads, and even the casing etc. This does NOT have to match, as a quick Google will often reveal different capacity drives with the same DCM. Mine for example is shared with a WD5000BMVW 500GB, and a WD3200BMVV 320GB, so these morons such as fzabkar on forums like HDDGuru are talking through their arses by saying they’re unique and that the ROM chip must be swapped. Most of the firmware and S.M.A.R.T data is stored on a reserved section of the platter, making their claims even more irrelevant.

DCX: TH16X3FZE – This is the drive’s Batch number, so that Western Digital know which factory it came from, what date it was made, and probably the engineer who soak tested it and which line it rolled off. This DOES NOT need to match for a donor board, it is IRRELEVANT.

To sum up, the only bits you really need to worry about is the Model/Firmware string. I have Western Digital drives as small as 10GB and as large as 2TB in my portfolio that I’ve used my own guidelines on over the years and I’ve never had any head/track/sector/cylinder issues, the drives have often worked better than they did with their original boards.

I’ve swapped 1,000 Western Digital drive boards over the past 6 years like this using my own guidelines, and each drive is perfect, even my own drives. I consider myself a data recovery professional, as I have performed many platter and arm swaps in a friend’s clean room as well as board swap and data recovery, especially on Western Digital drives, as I love them and have never used any other drives in my own computers.

fzabkar isn’t even a professional, as he uses phrases like “will most probably not work”, and “as far as I’m aware”, which sounds like he’s just using pure guesswork. I’m not, I’ve been doing this many years and have yet to have a WD not pass a board swap.


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Today a customer brought his Core 2 Duo desktop in, saying “It wouldn’t load Windows”, that was all he could tell me. Powering his box up, the hard drive was being recognised, but it wasn’t spinning, I didn’t even hear the “start-buzz” (the buzzing noise some drives make as the drive motor starts, the noise is the voice coils in the motor recieving the high start current), on a lot of desktop WD’s it’s like a “wuudearrkk” sound, this one was totally dead.

The arms on a drive will not unlock from the park clamp until the platters are spinning and the air vacuum inside the drive creates centrifugal inertia, along with the arm actuator coils activating, to gently release the heads together.

Upon removing the drive from the computer, and unscrewing the control board, it was apparent that the SMOOTH motor spindle starter & driver chip had failed catastrophically, along with the Q8 3.3v voltage regulator for the spindle driver, as my picture below illustrates. The thing that struck me on his system was that he was booting Windows from an old IDE drive (the WD2500), yet his data drive was a SATA Samsung! They should have been the other way round!

It is apparent that the chip has overheated and started to burn up, possibly because the drive either has failed bearings that caused high resistance, or it has simply shorted and died.

To fix this all you need to do is find a board with matching part number and firmware, such as WD2500KS-00MJB0. A lot of forum morons say that the DCM (Drive Configuration Matrix) also has to match otherwise you’ll need to desolder the ROM chip, THIS IS NOT TRUE. I have recovered at least 1,000 Western Digital drives in the last 6 years by board transplant, and we’re talking from old 20GB WD200’s up to new WD20EARS 2TB drives, and all I have ever done is match part number with firmware. The DCM is simply an architecture code, it is NOT a firmware date code. DCM’s are often identical on different capacity drives! The firmware revision is combined with the part number, like WD1200UE-00KVT0. The secondary code after the dash is the firmware.

Only these two have to match on a donor. If any of these so-called professionals on forums tell you otherwise, they obviously don’t know their job properly and are trying to overcharge you for unnecessary work.

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I updated Firefox today, and was greeted with the follwing message:

Different by Design

Thanks for upgrading! You’re now ready to enjoy the very latest in speed, flexibility and security. As a non-profit, we’re free to innovate on your behalf without any pressure to compromise. That means a better experience for you and a brighter future for the Web.

Hahaha, I burst out laughing! If they’re free from pressure to compromise, then WHY are they so keen to copy Google with Chrome’s limited dumbed down interface? It seems like the programmer’s version of peer pressure to me. Google’s getting bigger, sticking its fingers in pies it knows nothing about (Google +, Google Drive, and all the other flopped stuff they’ve canned in the past) so Mozilla are trying to claw back market share. All because Chrome is sneaklily bundled with installers, whereupon 99% of users are the Next, Next, Next and Finish button clicking types, so Chrome magically gets big market share thanks to usage data and setting itself as default browser after being craftily installed.

It was only ever since that Chrome-browser-for-netbooks crap came along that Mozilla decided to follow suit and give the majority of us with proper systems and big screens a limited UI by default, to supposedly give us more “screen real-estate”. We don’t want, need, nor asked for it. A lot of sites are bad enough where they are centered to 800px wide, leaving tons of whitespace on a 1200px + display. God help standard white page with black text HTML pages, they look terrible.

Mozilla may not have investors and directors to please, but they can’t keep copying competition. Seamonkey is based on Mozilla, but still has a full UI with menus, they go their own way, which is the way Firefox used to be. Google’s ideas are never inventions, they themselves copy stuff that’s already done. Like GMail, that is simply a nice frontend for an Exchange server somewhere, and the GMail Labs, they’re just plugins for said frontend. They like to make people think they invent, but all they do is take stuff that exists and make it look nicer, or in the latest GMail look, make it worse.

JavaScript email frontends have existed for years. I use Roundcube, that trounces GMail in every way possible, and it’s open source and supports plugins. Companies need to start inventing something new rather than copying the existing.

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