Hard drive dead? WD5000AAKS

I changed my PSU and now my drive is missing. I am in denial over it being dead, so I have come here to find out if there is anything I can try.

The drive is a WD5000AAKS 500gb Caviar Blue. The drive is missing in the BIOS and makes no noise or vibration on startup. It is less than a year old.

Is there anything that I can try to bring it back?


It appears that your drive may have a PCB fault. Measure the resistances of the 12V and 5V TVS diodes (D4 and D3), and zero-ohm resistors R64 and R67, located near the SATA power connector. Set your multimeter on the 200 ohms range.

Depending on what you find, there may be an easy, no-cost DIY fix.

Okay, I have a multimeter but that is slightly techinical for me. I don’t mean to be a burden, but any chance of a picture with where to place the multimeter etc?


If this is your board …


… then D4, D3, R64, and R67 are located in the top right corner.

To test the resistances of each component with a multimeter (DMM), you need to set the DMM to the 200 ohms resistance range. Connect the black probe lead to the DMM’s COM banana socket, and the red probe to the Volt/Ohm socket. Then connect the probe tips to each side of the component being tested. If the meter reads near zero, then the diode is shorted. Note that the meter leads will have a finite resistance which you can verify by touching the probe tips together.

This tutorial should help you:

Read “Example 1. Testing a resistor”.

The readings from the multimeter are;

R64 - 00.6

R67 - 00.6

D3 - No reading

D4 - No reading

I am guessing this means they both need replacing? Could I not buy a new PCB?


I’m assuming that by “no reading” you mean that the meter overranges, in which case all four components are testing OK.

You can’t just swap the PCB. This is because each PCB stores unique, drive specific information. These data must be transferred from patient to donor. Some WD drives store these data in an 8-pin serial flash memoy chip, usually at location U12. However your U12 is unpopulated, meaning that the “adaptives” are internal to the Marvell MCU (big “M”).

When searching for a replacement PCB, ask your supplier (eg http://www.hdd-parts.com or http://www.onepcbsolution.com)) if he offers a ROM or firmware transfer service. The cost should be in the range of US$10 - $20.

BTW, can you see any burn marks, especially around the SMOOTH chip? Is the drive completely silent, or does it sound or vibrate as if the motor is seized?

Sorry for the late reply.

By no reading, I mean the multimeter does not change from its standby screen. If the meter overranges should I not set the MM to a higher setting?

This part;

‘Some WD drives store these data in an 8-pin serial flash memoy chip, usually at location U12. However your U12 is unpopulated, meaning that the “adaptives” are internal to the Marvell MCU (big “M”).’

goes over my head. Any chance of a simplified version?

Unfortunately I am in the UK, so neither of those sites are much help. Do you know of a UK site you would recommend?

There no burn marks around the SMOOTH chip, or anywhere else on the board. When I boot up the PC the drive is completely silent. No vibration, no noise.

Components are identified on the PCB using circuit references. For example, Rnn, Cnn, Lnn, Dnn, Qnn, and Unn designate a resistor, capacitor, inductor, diode, transistor, and integrated circuit, respectively.

Manufacturers often use the same PCB design for different models. Therefore you will often see vacant (ie unpopulated) areas corresponding to functions which are optional in lower models. In your case there is a vacant location at U12 which is wired to accept an 8-pin serial flash memory IC. The reason for this is that there are two versions of the MCU (microcontroller) chip – one relies on external flash memory, while the other has flash memory incorporated inside it. Yours is the latter. If it had been the former, then transferring the “adaptive” data would only have required transferring the external flash chip to the donor PCB. That’s a relatively simple soldering job. Moving the MCU, OTOH, requires an SMT rework station.

I don’t know of any UK supplier. However, I believe at least one of the aforementioned vendors has an international service for $3. That said, if the MCU is dead, then extracting its “adaptive” data will be impossible.

There are a few more measurements you could take to narrow down the fault, but essentially it will just be a post mortem. It might be an instructive exercise, though … for you and me both.

Well I am willing to learn, and to try anything you can think of. That is of course if you have the time and patience. :slight_smile: I would be very grateful.

I have emailed a company in the UK who charge £360 (plus a new drive to transfer to) to recover my data and will not attempt a PCB swap. I also emailed HDD-parts and they do not have my PCB in stock. Your second link does not seem to work.

Thanks again!

The second link has been messed up by the closing bracket.

As for your board, I have been through this with another individual. In his case the MCU was shorted. Hopefully you will have better luck.

The first thing I would do is to confirm that there are no shorts on any of the supply rails. To this end you would need to measure the resistance between each supply and ground. In addition to the +5V and +12V supplies at the SATA power connector, the board generates its own internal supplies from several switchmode DC-DC converters, and one linear regulator. One is the Vcore for the MCU, another is the -5V for the preamp, and there are either one or two Vio supplies for the MCU, SDRAM, and serial flash.

Could you measure the resistance between ground (at the SATA power connector) and each of Vio and Vcc in this photo clip?

Also measure the resistance between ground and pin #1 of the SDRAM:

Determine which of the following 20 pins are connected to ground, and which is connected to +5V:

Also determine which of the preamp pins are connected to the Voice Coil Motor (VCM) sense resistors, R8 and R9:

Here are the onboard DC-DC converters:

Measure the resistances of each resistor (R48, R45, R47), each inductor (L), each capacitor ©, and each diode (D). Also measure the resistance between the non-striped end (anode) of diode D2 and each pin in the preamp connector. The pin that measures 0 ohms will be the -5V supply.

Also measure the resistance between each L and ground.

Finally measure the resistance between each of the leftmost two inductors and each of the SDRAM and serial flash supply pins.

These measurements should map out the layout of the onboard supplies, and identify which components are powered from each supply.

I would love to know the outcome of this thread.

I have the same problem. I have not pulled the bd yet to do the measurements since I need to buy a tiny torx bit. Mine is:

model # wd5000aaks

s/n: wcas81082376

Will the ts procedures and measurments be the same for mine?



I did the measurments and got these values:

d3 61.2

d4 19.1

r64 0.6

r67 0.4

I checked the bd for burnt pts under a microscope and did not see any.

What does this tell you about the next step for me?



Okay, I’m back! Sorry for the delay again.

I have since taken this drive to a guy who has some pretty good kit and he took a look at it and confirmed it is indeed dead.  

Fzabkar; My PCB if different slightly to the one in the pics. Unfortunately I cannot find which is the replacement part of the board in which I would need to test.

I have now come around to accepting the death of my drive and have learnt an important lesson. Always back up!!

Is there a 500gb WD drive anyone would recommend? I have since read that the WD5000AAKS has a weakness against frying the board so I do not fancy buying another.

I have also read that the WD20EARS is also prone to losing data. This is my other drive. Is this internet talk or am I quite unlucky?

Thanks again Fzabkar! :slight_smile:

That doesn’t sound promising at all. Im about to replace my PSU with a new one and currently i have four 5000AAKS discs connected. Im thinking of buying a 2 terrabyte disk to backup it to before any PSU change would kill them.

Is this a WD issue or can this happen on any brand?

edit: I already did a PSU change before and nothing happened fortunatly. On a side note my disks has run flawlessy for about three years but failed running in RAID.

I think that I was just unlucky. Though I would definately recommend buying a 2TB drive and back it all up before you start.

My WD20EARS was only £70ish from Amazon. Not worth losing precious data for that kind of price.

wddanie, neither of the diodes tests shorted, although the resistances appear low.

My next step would be to check the onboard supplies for shorts, as in my previous post.

Hi fzabkar,

This thread is the closest thing I have found to fixing my (outdated) hard drive. I did all the measurements you requested and they are below: There is one picture detailing the layout of the preamp pins also. I’m willing to do just about anything to revive this drive if I can. These measurements were all taken on a range of 200 Ohms, let me know if they will need to be redone on a higher scale.

R64: 0.7
R67: 0.6
D3: out of range
D4: out of range

No burning around SMOOTH chip

No U12 chip

Vio to ground: out of range
Vcc to ground: out of range
Pin #1 of SDRAM to ground: out of range

Preamp Contacts: See http://img8.imageshack.us/img8/3962/wd5000aakspreamplabelle.jpg

R8, R9: 1.1

R45: 0.7
R47: 0.7
R48: 0.6

*C24: 90 and falling
*C25: 95 and falling
C27: No reading
C39: No reading
C37: No reading
C next to C37: No reading

L: 0.6 (for all)
L2 to ground: 0.7
L (other two leftmost) to ground: ~100 and falling
L (all three shown) to SDRAM supply pin: out of range
L (all three shown) to serial flash Vcc: out of range

*D1: 95 and falling
D2: out of range
D2 to Preamp pins: See picture

The values that bothered me are astricked (*). Let me know your opinion, but I didn’t think C24, C25, and D1 shouldn’t have such low resistances. I appreciate all your help and I look forward to your reply.

Sorry, I’ve been away from this forum for a while. Thanks for your excellent feedback.

Q3, D1, R45, C24, C25, and the two leftmost inductors appear to form the DC-DC converter for the Vcore supply.

Q2, D2, L2, R47, and C39 appear to constitute the DC-DC converter for the preamp’s -5V supply.

The SDRAM would be powered from the Vio output of the linear regulator (transistor with DA marking).

From your measurements, I see that there are no shorts on any of the supplies, and both TVS diodes (D3 and D4) are OK.

My next step would be to power up the board on its own and measure the Vio, Vcore, and -5V supplies. Vcore would be accessible at R45. Vio may be more readily and safely accessible at the jumper block (the inputs would be connected to Vio via pull-up resistors).

I am also experiencing a drive failure for a WD5000AAKS-00YGA0 SATA 500GB Caviar Blue drive.  It powers up and spins the drive, but then clicks 6 times, followed by a pause, then 2 times, followed by a pause, and 2 more times.  Then it repeats the same 6/2/2 click cycle and finally Bios reports that there is a drive error and it never registers through the Bios.

I took off the controller board, and measured the TVS diodes and resisters as follows:

R64 - out of range  (on my board this looks like R54)

R67 - 00.4

D3 - No reading / no-tone

D4 - 00.4 / tone

From what I gather, this sounds like both R64 and D4 are not working properly.  Is the fix to remove D4 and to short R64 with a wire or a piece of solder?

Please advise any additional troubleshooting steps before I take drastic action.