I have 1TB WD10EADS drive which not working for now after I put in the built-in front SATA dock in my case. After check in PCB board, I found that smooth chip was fired (I also attach picture of PCB).
I have a multimeter for now, is it possible to make a DIY test for this PCB board (such as test a preamp or diode resistance)

And what can i do to get my data from this drive. Switch and transfer eerom to a donor board?

Thank you

Here is my drive detail

WD10EADS-00M2B0
WWN : 50014EE2AE360BDA
Date : 22 oct 2009
DCM : HBRCNV2MGB
LBA : 1953525168
Product of Thailand

PCB 2060-701640-002 REV A
Sticker 2061-701640-202 03PD8 XC 8R25 10TX L 0001150 0151

No need to test the smooth chip is fried and so the motor will not turn (motor controller chip) so get a new PCB and swap out your ROM

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Iorana Haraharaini

If you are unable to transfer the 8-pin flash memory chip at location U12, then the following PCB supplier will do it for you for free:
http://www.donordrives.com

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A backup a day keeps DR away.

I have read from fzabkar post in other board or topic he said that smooth chip damage may also damage "preamp" which locate in drive not on PCB.
In worst case, preamp is damaged, I will send it to DR lab because head stack is need to be chaged.
But if I lucky enough preamp is fine, I will find a PCB board and swap it by myself.

So that why I would like to know Preamp is damaged or not?

It is quite possible that your preamp is damaged. However another user with similar SMOOTH damage managed to recover his data, so with any luck you may get out of trouble for only US$50.

If you need a head swap, then contact http://myharddrivedied.com. They offer fixed price data recovery for US$800 plus parts. The proprietor, Scott Moulton, is a valued member of this forum.

As for resistance tests, set your multimeter on the 200 ohms scale and measure the resistance between pin #2 (Ground) and each of pins #4 and #6 on the 20-pin HDA connector on the body of the drive. This connector mates with the J1 contacts on the PCB.

Pins 4 & 6 are the positive and negative supplies for the preamp. I believe pin #2 is Ground, but you may like to confirm this by testing for continuity with a known PCB ground, eg the screw holes.

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A backup a day keeps DR away.

Thank you for your testing step.

Here is the testing result.
I use multimeter to make a resistance testing with my 20 pin connector on my drive. I am not sure what is number of each pin, so I label in the picture and do a resistance testing on every pin. I think Pins #1 (in my pic) on HDA connector is ground because the resistance between screw hole on HDA is close to zero.

Am I doing it correctly ? If you want me to test another thing, please tell me.


Thank you

Thanks. It appears from your measurements that pin #1 is ground, not pin #2.

Pin #4 and #6 must be the supplies, in which case there is no short circuit to ground. This doesn't prove that the preamp isn't damaged, but it is probably OK.

The motor controller chip isn't damaged on the side that drives the spindle motor, but you still might like to confirm the resistance readings between each of the motor terminals. There will be three windings and one common terminal. The winding-to-winding resistance should be twice the winding-to-common resistance. A value of the order of 1 ohm is OK. If one winding differs significantly from the others, then that would be reason for concern. Otherwise if the motor tests OK, then go ahead and order a new board ... with a firmware transfer.

Good luck.

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A backup a day keeps DR away.

warning here, despite good intentions, you can damage your preamp like this, specially when using a cheap DMM. Although this method can be used, i would add a disclaimer to use with caution

A cheap DMM is harmless. You can prove it to yourself.

See samsung-hdd-hd753lj-dead-t15374.html

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A backup a day keeps DR away.

Well maybe talk to some of the people who have fried a preamp with a multimeter, I know plenty

I am not saying that using a cheap multimeter will always and in every case damage the preamp, i am only saying that it has happened to many people on many occasion and for the OP and anyone reading this post to proceed with caution.

Sure, if you tell me who they are. ;-)

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A backup a day keeps DR away.

I've been trying to recall any situation where a test instrument of any kind was responsible for damage, but I can't recall any in my experience. The only thing that comes to mind is a warning from Ford to avoid using certain testers on oxygen sensors, the reason being that these inject a current into the device that may be of sufficient magnitude to disturb its calibration. I understand that heads are susceptible to damage from ESD, but I can't see that a preamp is any different to any other silicon that I have encountered. In the bad old days CMOS ICs were prone to latchup if a voltage on any input pin exceeded the supply rail, but damage only ensued if there was no current limiting.

As for your colleagues, I would like to ask them why they were measuring the preamp. If it was because they suspected it was faulty, then how could they be certain that the failure was due to their testing methodology? In my career I have reverse engineered numerous microprocessor based circuits. In order to speed up the work, I used the continuity (diode test) function of my meter to trace connections between ICs. Some microcontrollers would have 64 or more pins. In order to locate a particular pin, I would buzz the entire IC on all four sides. I would do this for each pin, and I never damaged any board. And these were sensitive CMOS devices. Since the meter outputs 1mA on this range, and since its open circuit voltage is 3V, I find it extremely difficult to understand why a preamp would be harmed by 0.5V and 0.1mA, these being the typical specs for a cheap DMM.

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A backup a day keeps DR away.

No use to issue warning here there seem to be only one person who knows it all and is correct. We are fighting a battle we can not win and a person who has an answer for all. We do not know anything anymore around here and it seems that he is the only person here to help people and we have nothing to say on this one. I feel like we should just turn over the forum to him and allow him to answer all the posts here and stop trying to help people at all. This is what it is starting to look like now. If we give good advise we are told no this is not true. I guess we never see this happen and we are wrong to suggest to people to proceed with caution on this one. I give up and let him answer now all the posts here. There is no other way on this one. Leave the forum to him now and start a new one. Sorry but this is what it feels like around here now.

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Iorana Haraharaini

Here is the motor terminals testing result. I think it OK.



Do you think that, it is possible for DIY fixing ? I really worry about preamp which I cannot change it my self.
Should I start order a new PCB board or not?


Thank you

I've grown to like fzabkar's careless disregard for people's data. It cuts down on these 99% recovery rate, we don't step near a clean room, cheap recovery firms and brings more expensive head transplants into my shop. My hat off to you Franc. Let it be another great and profitable year of internal repairs.

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Buy your friends Toshiba\Hitachi and your enemies Seagate.

Ask if you can get a full refund or someone will pay DR expenses (you choose who from) if your DIY won't work or you'll fry something else. Simple.

I don't think anyone here has a true appreciation for the delicate electrical nature of a preamp. These devices can be damaged with as little as 15 volts of static electricity. This is unlike many other forms of chips like USB interfaces and chips that connect to connectors for interfacing, those have plenty of protection built-in. These little preamps have no protection against stray voltages whatsoever. They can't! Not if they're to handle the low signal levels coming in from the heads. Protection devices would only serve to decrease bandwidth and sensitivity.

It's generally not common for a DMM go around damaging components. But if any static electricity builds up in and on the test equipment then all bets are off. And that's the problem. Grounding and dissipating static is a must, and that is where errors are made. Not so much as in using the cheaper equipment, but how it's used. A good quality Fluke or HP, is going to have an anti-static housing, and better grounding, and lower current. Those are things that will help minimize risk and damage.

Simple tricks like grounding and touching probes to housings first make big differences in preventing blow-ups.

2 things in favor of the preamp is that they are mounted on the metal arm and generally well grounded.

And finally, if you're soldering these things, then use a grounded DC soldering iron.

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On a clear disk you can seek forever.

Not ANYONE. Someone still remember when a drive was sent to me years ago and the preamp chip on the flex was changed (there was little or no alternative as it was one of the bad puppies where you would need 100 headstacks in order to find the "least problematic"). Successfully of course.

Ignorance is a bad beast. Sum to ignorance the fact of never having worked with real ACTUAL stuff and a spoon of incoscience.... and then you know where data loss starts.

I agree, the motor seems OK. And yes, go ahead and order a board (and firmware transfer).

Very best of luck.

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A backup a day keeps DR away.

According to the motor chip condition, there's high possibility that the preamp is damaged as well.

Replace the PCB, transfer the original ROM and I wish you luck ( which you will need it )

Good luck.