yep, however the pcb might have further issue, i mean that could be also an electrical faulty.

_________________
My firmware database:
https://mega.nz/folder/O01DkBRI

can you test components measures as suggest you fzabkar?

i think this is the way.

them we wil know if PCB is burned or not
(most problably burned)

and them we can test for solve this isue, or maybe donnor PCB needed.

Hi Michael Chiklis & hhddrec,

Thx for your comments. Unfortunately my multimeter is too old (built in the 80's) and it can't test the diodes. I ordered a new one today that I ll receive tomorrow. I will let you know if the tvs on the sata pcb are ok or not.

Best regards
0383A

I not important if multimeter is old or new one.

For testing Diodes you must test for resistence.
in this way if you test from one way to the other you must get near to 0 and in the other side you must get near infinite

Well it is too late I got my new multimeter this morning. and trust me the old one was really old. I even had the user guide, and Google could not find it. One question Where is the + and the - on the TVS diodes?

I don't see the dark line mentioned in the PDF document!

thank you for your assistance

best regards
0383A

So here are the value of the TVS diode:

12V TVS diode: 0.028
D3 5V TVS diode: 0.401

Thanks the new multimeter who inform if connect the black and red to the correct +/- or not!

Now I will have to check the ohms on R64 and R67

For the R64 & R67 I have to measure the resistance (in Ohms value)
is that correct?

if this is right, here are the values measured:
R64: 0.5
R67: 0.5

Thanks in advance for your feedback.

Best regards
0383A

Check that diode again.

Hi dick,

Checked again, now I have 0.026

Best regards

0383A

Check them both again in both directions using the diode check function if the meter has it.
Write down the results and post them here.

Hi dick,

I have taken 2 macro pictures of the 12V TVS diode which I believe shows something not original. There is like a bump on the top of it near GP or GR letters. Here are the pictures:

Looks like Diode badly!

Yes it has the function, the multimeter is a Velleman DVM4200.

The TVS D3 diode has 0.400 in one way, 0L if I inverse red and black. 0L on the display means wrong way of black/red contacts.

Looks like, I ll have to ship both PCBs (the sata one and the usb one) to the Data recovery center for replacement?

No!

You can carefully remove the damaged tvs diode. If you are lucky the drive will work.

So, you mean to unsolder the diode. Do I have to replace it with another one?

Should I tell you how my hands were trembling today when I took the 1st measure (like if I do something wrong, I kill everything on the pcb)?

Sometimes My Surname could be Mr Bean.

Unsoldering bad TVS diodes could work, but usually i prefer to replace them.
If something goes wrong when you will apply again the power supply you might kill head pre-amp without TVS (assuming that pre-amp is not already damaged).
By using new TVS, head pre-amp and pcb circuit should be safer.

If you want i can do this job for you, i have TVS diodes for replacement, i'm in Italy (not far from Switzerland)

_________________
My firmware database:
https://mega.nz/folder/O01DkBRI

Hi Michael Chiklis,

thanks for your reply, were are you in Italy?

Kind regards

0383A

If the drive works after removing the fused tvs and replacing it then you will need to buy in the usb pcb to be able to decrypt your data. At this moment I think you have a slightly better than even chance of success. Good luck!

I have seen many similar cases in WD's forums. The usual result is a shorted 12V TVS diode. If R64 survives, as it has in the OP's case, then the drive is usually OK after removing the diode. You can use flush cutters to do this. You don't actually need to desolder the diode. In fact you may even be able to use finger nail clippers. Just be careful not to lift the copper tracks.

A local TV/AV repair shop should be able to replace the diode. My FAQ lists suitable replacements and sources.

http://www.users.on.net/~fzabkar/HDD/TVS_diode_FAQ.html

There are ways to repair the bridge PCB without having to purchase any parts, but you would need a little soldering skill and some understanding of electronics.

_________________
A backup a day keeps DR away.