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Data recovery and disk repair questions and discussions related to old-fashioned SATA, SAS, SCSI, IDE, MFM hard drives - any type of storage device that has moving parts
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WD10EAVS overvoltage (wrong power supply), bad TVS diode?

August 13th, 2011, 11:13

My brother lost the power cord for his 1TB SATA WD external drive and decided that perhaps plugging his 18v laptop cord would do the trick. Needless to say, the enclosure (12v) didn't appreciate the extra 6 volts and poof, now the drive is dead.

I'm trying to see if I can help him recover his pictures he was storing on the drive. I removed the drive from the enclosure and plugged it into a spare computer. I smell magic smoke. The drive spins up, but never is recognized by the computer. My brother is a poor college student (so DR center is out of the question).

The drive is a 1TB WD10EAVS.

After some judicious Googling, one theory is that an overvoltage from plugging in a laptop power supply commonly causes the TVS diode near the SATA power connector to short, but may leave the rest of the logic board and internal preamps fine.

Since I have no experience with TVS diodes, I have included closeup pictures of the suspected diode. I tested both D3 and D4 with resistance and diode functions with a multimeter:
D3: diode: high one way, low the other Ohms: 0 (open) both ways
D4: diode: very low both ways (001) Ohms: 005 (lowest setting) both ways

If I'm reading this right, this means that the J3 TVS diode is still good, but the J4 diode is shot.

I've read other success stories of people unsoldering the bad diode (disabling 12v protection) and powering the drive up long enough the copy the data off. What do you think? Is my analysis correct? I wanted to run my idea by the experts before I do something crazy.

Thanks very much for your help.
IMG_9490.JPG
Closeup of the J3 and J4 diodes near the SATA connector.
Attachments
IMG_9489.JPG
Logic Board

Re: WD10EAVS overvoltage (wrong power supply), bad TVS diode

August 13th, 2011, 12:50

If the TVS was the problem then drive wouldn't spin up at all in my experience.

Is the drive being detected in the BIOS?

What external enclosure is it from? The WD enclosures like the My Book for example has a chip (initio inic-1607) on the bridge board inside the enclosure that encrypts the data. So if you remove the drive from the enclosure and plug it directly into your SATA port on a PC you won't be able to read the data as it's encrypted.

My guess would be that the bridge board inside the enclosure is wrecked from the overvoltage. Maybe inspect it for burnt components and post a pic of it. Best bet is to fix that board if it's damaged.

Re: WD10EAVS overvoltage (wrong power supply), bad TVS diode

April 24th, 2012, 8:47

Ditto.!
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