Dead hard drive - can I swap electronic boards?

Okay, my friend has an IDE 3.5" Western Digital WD Caviar 205AA 20.5GB harddrive. Other info on the hard drive is: Mfg Date 5/19/2000, LBA 40079088, Model WD205AA-00ANA0

She said the computer stopped working after several rounds of electrical surges due to an ice storm this past winter.

So I pulled the hard drive, put in another one that I had and it powered up just fine inside the tower. I also have an external IDE to USB cable with external power that I've used several times to power hard drives outside the box to move data to another PC by USB (so it works), but on her HDD still no power.

I know there are professional services that could recover the data (she really wants/needs the data, but she's not willing to pay what they're asking - one quote was $700). I really think the electronic board on the HDD is probably what is dead.

So my question is this...

If I found another identical HDD could I possibly pull the electronic board off it and place it on the defective HDD? Anyone ever done this? I've heard of this, but I'm struggling to find any documentation on it. Also, I've heard that the HDD's have to be identical for the electronic boards to match and if that's so, does anyone know what determines "identical"? Is it the model #? I'm asking obviously because I don't have one that's identical laying around, but there's a good chance that I could find one on ebay. A 20GB IDE hard drive probably doesn't cost that much so she's willing to give it a try for $20 bucks or so.

P.S. I had already froze the HDD in the freezer to see if that would unstick it assuming that it might be stuck and that didn't help either (not sure where I picked up that trick, but it's worked twice for me over the years - this time it didn't help).

I smashed up some old hard drives, and I really doubt if you can do that. The board is hard wired to the read/write heads, there's no ribbon cable or anything like that.

what your thinking about switching the boards only works for cdrom/dvd rom/rw/ and optical disc based drive.

okay, that's what I needed to know - thanks for the info!

actually, kmham is correct and it is possible to swap the controller boards from one hard drive to another in the effort to repair the drive. But this is not something you want to do to "refurbish" a hard drive, this should only be done for data recovery as there is no telling how long the drive will remain working. For most of the drive failures, a large majority of hardware problems are linked to that one little PCB on the back of the hard drive, it is MUCH less common for there to be issues with the platters, spindle, head, and so forth.

Replacing the pcb on the back of the hard drive is a very common thing to be done by people who deal with data recoveries on a hard drive. Gotta give a shout out to Scott Moulton of Forensic Strategy Services, LLC who is without a doubt THE MASTER of hard drive recoveries in my mind, his speeches at various trade shows taught me everything I needed to know to do my own. You may want to look up his videos on youtube, he has a few different presentations but his DEFCON 14 presentation will explain a lot of what you want to know.

But basically, if you want to do it you need to find the EXACT SAME hard drive. The hard drive manufacturers may create the platters and internal logic/arm/head/ etc but that little PCB board on the underside of the drive may be made by 10 different companies over the course of a month. One week it could be made in China, next week it could be in Korea. Look VERY closely at the model number and the manufacturing date, these are very important. If you can find a drive that is as close a match as possible to what you have, chances are good that it will work. A good indication that it will not work, is if you see your pcb looks different than the one your thinking about stripping, 9 times out of 10 it will not work. The drive will detect the firmware and attempt to do its thing, but you will not be able to read your data. The firmware MUST be the same version, each drive is programmed to use that specific firmware revision. The drive is low level formatted at the time of production to work with that revision. You cannot change that.

Scott recommends you go no longer than 2 months out from the date your drive was made, to the date on the donor hard drive. So if yours was made May 19th, do not go 2 months beyond that. Most people would try to go 2-4 weeks. On modern drives this board is connected by a small ribbon cable, sort of like what you see in laptops. These boards are not soldered to the drive or glued down, they are usually held in place with 4 screws (sometimes they use hex type security screws). Sometimes the ribbon cable is absent and your board is resting on contacts. It can vary a bit, but they are in general, always removable.

For a novice this is even a simple task, but beyond this your going into an area of expertise where skilled people get paid a lot of money because its not easy. Swapping heads and platters is doable in some cases, but its much more complicated. If the platters for example are scratched or the head is damaged, odds are that data is gone and very little could be recovered even by the best in the business.

So if you wanna swap the boards, its worth a shot. But look up some of Scott's presentations, it'll bring you up to speed


If there is data on the drive that you MUST recover, I'd send it off to the proper company for a recovery. If there is stuff on there you want but you dont mind risking for the sake of a learning experience, go for it


So yes its doable, but under the right conditions.

Like Stang said: get the same drive with the same firmware, and it'll work. As long as it's the PCB that's crapped out, and not the drive-assembly itself of course.

But if she wants her data back, why not just recover it from one of her backups? That's what they're for...

WOW! Thanks for all that info stang - very much appreciated. I'll go do the research you suggested now.

Will a number written on the face of the HDD tell me the firmware or is that just something I have to get lucky on by getting something with a MFG date that is really close to 5/19/2000?

Also, I'm not sure I follow what you mean by "why not just recover it from one of her backups?" She didn't have anything backed up and the sole HDD stopped spinning. Please elaborate if there's another option for me that I'm not seeing.

stang - I found a PCB board on ebay with most of the main #'s matching my problem HDD and with a date of 6/24/2000 (the defaulty HDD that I'm trying to recover is dated 5/19/2000) - what do you think of this - close enough? (P.S. it's tested and guaranteed to work by a Power Seller )

Problem HDD model is WD205AA-00ANA0
and the one on ebay is WD205AA-40BAA0

Is the first part of the model # matching okay, or does the entire # need to match?

The basic rule of thumb is that if they look the same (ie the same layout of components, the same memory buffer, controller, firmware and any other mis. components such as a bridge chip) and the boards contain the same firmware version, then its likely to work. The manufacturing date is usually the key to identifying whether or not the two boards will be a match. There may also be a identification number printed directly on the PCB that can help identify how closely matched the two boards are.

When it comes to identifying a model number, typically the break down would be Maker (WD), Model (205=20.5gb/6.8gb per platter) Revision (AA). The first set matching indicates that you have the same model, the second set should be a unique identification but to be honest I am not sure how that set is generated and what (if anything) it would have in relation to the model. If the two PCBs look identical, look at the make and model of the chips on the board. If the components mach up to yours then odds are it will work just fine.

To be perfectly honest the handful of times I have done this, the only thing I checked was that the date code was close and that the same firmware chip was used. In those cases the PCB looked identical and the same controllers were used, so I never took much note of anything else.

Basically all you can do is google some numbers listed on each component on the board, identify what each item is, and ensure both boards use the same models.

Picking up a drive that I have here, all I do is read off the make and model of each chip until I find the flashrom, such in this image. So if I was to look for a compatible board for this drive, I would be looking for this chip to appear on a pcb that contains other similar chips (such as the marvel controller and the SI cache also pictured), and assuming the model matches and the date code is within 2 months (preferably 2 weeks) then I'd say its good enough to swap.

But as Itsacon mentioned, this is all assuming this board is the problem :P