If I connect the drive via USB the OS does not recognize the drive. If I listen the sound carefully it does a continuous sound (1-2sec like dial-up modem connecting) for 15sec. After that the sound stops and LED starts to blink. I changed the USB cable, but the problem was not resolved.

If I disassemble the case, I am unable to connect it throught SATA, because the USB circuit board is mounted on HDD.

My questions are:
- Can I replace the circuit board (what type?) with another one that has SATA connector?
- Is there some sort of encryption on the circuit board?
- Are there any other options to recover the data?

Thank you for your help.

WD My Passport Essentials are encrypted via a chip on the PCB.

If you did swap the PCB over for a SATA one and manage to image the drive all your data would still be encrypted.
Try recording the sound & uploading it?
Could possibly be Siezed motor or Stiction? If so then sorry DIY is not an option.
Has it been dropped or knocked? The reason I ask is that, that could cause a siezed motor & improper disconnects or power cuts could cause stiction ie the head(s) get stuck to the platter(s).

Loki

This is 2.5" so seized motor is very unlikely.
I'm guessing this is stiction.

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Agreed but I always mention it just in case, as this would need to be confirmed by opening it up in a cleanroom enviourment.
Either way its not DIY

I agree.

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I did a little research about stiction. So the solution is to basicly open the drive, try to spin the disk with my hand and if everything goes OK the disk should spin properly?

If you want to destroy the drive, yes

If it was only that easy
The drive would need to be opened in a cleanroom enviourment to stop contamination of the platters.
Stiction is not an easy job, ie Heads can come off & get stuck to the platter, the platter can have damage where the head was stuck (might need a hardware imager), the released head could be faulty & not read or the arm can get bent slightly & you wouldnt know until you spun up the drive & it left scratches thus destorying your data. You need lots of practice on other drives to gain experience & of cause the tools.
A pro would unstick the head from the platter & then do a head swap from a donor.

Realistically DIY chances are 5% or less.

Loki

No, definitely not.

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I second that.
you also forget wobbly platters and bent axis...

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