Western Digital WD20EADS dead of overvoltage, TVS diodes?

[clsning]

hi to everyone. I've got a dead wd hdd because of overvoltage (19volt). I plugged my laptop power wrongly into the external enclosure. The enclosure is fine (checked it with other hard drives). The hard drive is dead and doesn't spin at all since then. By observation with bare eyes, it seems no physical damage to the PCB. After reading the forums, it looks like it maybe because of the TVS diodes. Can someone help and tell me how to find the TVS diode in my PCB? Is it OK to remove the TVS diodes and try to recover the data? I only need hard drive spin again once to copy out the data. Thank you very much.

Hard Drive:
Model: WD20EADS-00S2B0
Date: 15 APR 2010
DCM: HARCHV2ABB

PCB Info:
2061-771642-P00 09PD1

Here is the pictures of the actual PCB :

Many thanks

[networks]

Remove board and take a pic of the component side so we can see the tvs diode locations. Do you need a meter to check them if not sure how google has tons of info on checking diodes as does a search in thi forum.

[clsning]

Thank you for the quick reply. I will take a pic of the other side tomorrow.

[clsning]

here is the pic of the back of the PCB:

Thanks

[labtech]

See D3 and D4 for diode locations.
Test before remove.

[clsning]

I will test the D3 and D4 and report the results here. As I search in the forum, it's mentioned the zero ohm link is also needed to be tested. Could someone please tell me where those zero ohm links are? Thank you very much.

[loki]

See D3 and D4 for diode locations.
Test before remove.

Would also check R64 & R67 resistors - 0hms

Loki

[clsning]

Checked D3, D4, R64, R67 today. Both R64, R67 reads as 0.25, so I think this means they are fine. For D4, with the diode mode, the meter beeps, with the 200 ohm mode, it reads around 2.3 both ways. I think this means D4 is broken. For D3, it's fine with the diode mode, with the 200 ohm mode, it reads 0L both ways. Is this normal? I was thinking it should read a low ohm one way, 0L the other way. Was I wrong?

So at this stage, should I just remove D4 and try to read the data again? I will use the original external enclosure of the hard drive, so the power supply should be fine. Except for the power supply, is there any other risk for removing the D4?

Thank you all for the help.

[Nick_CT]

A TVS is shorted if it reads 0 ohms or very close to it.

[loki]

Checked D3, D4, R64, R67 today. Both R64, R67 reads as 0.25, so I think this means they are fine. For D4, with the diode mode, the meter beeps, with the 200 ohm mode, it reads around 2.3 both ways. I think this means D4 is broken. For D3, it's fine with the diode mode, with the 200 ohm mode, it reads 0L both ways. Is this normal? I was thinking it should read a low ohm one way, 0L the other way. Was I wrong?

So at this stage, should I just remove D4 and try to read the data again? I will use the original external enclosure of the hard drive, so the power supply should be fine. Except for the power supply, is there any other risk for removing the D4?

Thank you all for the help.

Here's a good PDF regarding diode testing http://www.electrosport.com/technical-r ... -guide.pdf

Loki

[hrcmumbai]

We will check with our stock for the same PCB and then reply soon as possible - hrcmumbai

[clsning]

Removed D4 today, reconnect the hard drive. It spins, all the data have been copied out. Thanks everyone for the big help. You saved a lot of memories of the family.

[labtech]

Be aware that you no longer have surge protection on that rail now. So, a power surge or PSU malfunction can permanently damage the drive.

[hoffy]

Hi guys, first post on this forum. It's fantastic that there's people here to help others recover their important information- a big thanks to everyone for helping out

I've gone and done the exact same thing (19V Laptop cable into 12V enclosure), and before I can take some photos to upload so I can start a thread asking (begging?) for help, I just wanted to know- what percentage of HDDs that fail due to having a laptop cable inserted into them end up only needing a diode removed before the data can be rescued?

Thanks guys

[Nick_CT]

There's no standard answer to your question. Here's a drive I got in yesterday which had a laptop power source connected to the enclosure the drive was in, the TVS (yellow) died but so did some other components (red) on the PCB.

Attachments

[hoffy]

Thanks for the reply.

I've lost two hard drives this week. Along with my motherboard (which necessitated a whole new PC as my system was so outdated), my $700 soundcard, an HDD enclosure (or two)...

It's been an expensive few days. Along with my car being broken into, getting a parket ticket the day before that, and a few other things going wrong... I'm assuming there's not much more room for bad luck in my life-

As you can imagine, I'm now expecting the HDD recovery to go perfectly well

[northwind]

Hi

Sorry to hear about the bad luck you came across the last dayz

Regarding the problem on your hard disk, generally speaking, chances are pretty good to have it recovered, as long as you trust someone who is skilled enough. It is quite rare (to my knowledge) that disks go beyond recovery just by plugging laptop adaptor to them. It happens, but quite rarely.
If only problem with PCB, it shouldn't be costly. If pre-amp is bad, just ask for a quote and then decide.

Good luck mate.

[fzabkar]

There's no standard answer to your question. Here's a drive I got in yesterday which had a laptop power source connected to the enclosure the drive was in, the TVS (yellow) died but so did some other components (red) on the PCB.

The burnt components are probably inductors. They would be used to filter high frequency noise. You can safely replace them with wire links.

Alternatively, just remove the 12V TVS diode and wire its cathode pad directly to the +12V pins at the SATA power connector.

Plenty of end users have done just that at Seagate's forums, so it's not beyond DIY.