WD80EFAX wont spin up

[fabianf]

Hi there,

my trainee made a big misstake. He connected a 19V powersupply to a NAS with 12V input. The result of it was, that the NAS wont turn on and both of the HDDs wont spin up.
If I connect now the HDD with a S-ATA powerconnector in the PC it also wont spinup. Also I cant see the disk in the BIOS. If i connect a external S-ATA powersupply to the disk the LED on the powersupply wont go off and no spin of the disk-> so I think the both diodes behind the connector are OK.
Cant see burned parts on the PCB or the disk.

Anyone an idea how to meassure the PCB?

best regards
Fabian

Attachments

[fzabkar]

Measure the 12V TVS diode and its associated fuse.

Attachments

[fabianf]

Thank u fzabkar,

left fuse and 12V TVS Diode was burned.

Fabian

[newtothis]

Hello,
I just found out I most likely have the same issue.
Is it possible to fix it in the PCB or I need a new one?

Thanks

[fzabkar]

Fixing the PCB would be less risky than transferring the two "ROMs".

Start by measuring the resistances of the TVS diodes and fuses.

TVS Diode FAQ:
http://www.hddoracle.com/viewtopic.php?f=100&t=86
http://users.on.net/~fzabkar/HDD/0B36131/

[Amarbir[CDR-Labs]]

Fixing the PCB would be less risky than transferring the two "ROMs".

Start by measuring the resistances of the TVS diodes and fuses.

TVS Diode FAQ:
http://www.hddoracle.com/viewtopic.php?f=100&t=86
http://users.on.net/~fzabkar/HDD/0B36131/

Well,
And The MCU

[fzabkar]

Fixing the PCB would be less risky than transferring the two "ROMs".

Start by measuring the resistances of the TVS diodes and fuses.

TVS Diode FAQ:
http://www.hddoracle.com/viewtopic.php?f=100&t=86
http://users.on.net/~fzabkar/HDD/0B36131/

Well,
And The MCU

Thanks.

Is there a list of MCU-locked PCBs? Are they all locked now?

[newtothis]

I removed the 12V diode. Didn't make it work :/

[newtothis]

Hello,
I've removed the 12v TVS diode, as it says in "9/ How do I repair my hard drive?" in provided link.
Result in the image.

Did not make it work.
Should I try shorting the fuse?

Attachments

[fzabkar]

You can try shorting the fuse, or replacing it. There are two e-fuses elsewhere on the PCB. These would be the second level of protection.

Did you actually measure anything, or did you just snip the diode on a whim?

[newtothis]

I measured the resistance. It was 1 in one direction and 125 in the other.
What should I do now?

[newtothis]

Should I replace those diodes with new ones?

[fzabkar]

It depends on your point of view. If you just want your data, then flowing a blob of solder over the open fuse will probably be OK. Otherwise, if you want to restore the drive's full protection, then replace the damaged diodes and fuses. It all depends on your soldering skill.

[fzabkar]

I measured the resistance. It was 1 in one direction and 125 in the other.
What should I do now?

Was that the diode or the fuse? If it was a diode, then that's OK (assuming "1" means over-range).

[newtothis]

Yes, it works after putting a blob of solder on the fuse. Thank you.
It it fine to have the drive working like this?
I assume the risk is only losing the drive if I make the same mistake again(?)

[fzabkar]

If you make the same mistake again, the e-fuse will most likely contain the damage ... I think.