The drive span up when i covered J1 with some ESD-safe tape.

That does appear to confirm that the preamp is dead.

_________________
A backup a day keeps DR away.

Then this is the end of the road for me :/
I would open up the drive and replace the arm, but im not sure how much a new one costs, and i dont think i have somewhere clean enough to do the job ^^

Sir ,
Kindly Explain The Second Part Again i think i missed something here .i would like to comment after that

_________________
Regards
Amarbir S Dhillon , Chandigarh Data Recovery Labs [India]
Logical,Semi Physical And Physical Data Recovery
Website-> http://www.chandigarhdatarecovery.com

after reading the messages about how the smooth controller got fried, could it be possible that the shorted preamp is forcing the power supply to ram more amps through the smooth chip and blowing it. Perhaps your home PSU is of a much higher amperage than then one you are using at work, so the board only gets hot and not blow because the PSU is at its max Amp output compared to your home one which could provide much more amps through the smooth chip.

If you can get hold of a second drive of the same type, then you can play with swapping heads in a clean room if you want. Perhaps find a simmuler drive with good heads and a bad PCB.

Shane

For a long time I used to think that WD's TVS diodes were configured as follows (because I was working from photographs and because I couldn't believe that anyone could be so stupid as to do it any other way):

In such a circuit, the fusible zero-ohm resistors (R64 and R67) would go open circuit whenever the TVS diodes were shorted by an overvoltage, thereby disconnecting the incoming supply from the remaining electronics. Other HDD manufacturers (Seagate and Samsung) also use series-connected protection devices (zero-ohm resistor, polyswitch).

However, when I eventually got my hands on one of these boards, I found that the actual arrangement was as follows:

Now consider what happens when the drive experiences an overvoltage.

Firstly the diode goes short circuit, causing the "resistor" R to appear as a direct short across the supply.

What happens next depends on the current limit of the external PSU. If the PSU is a 19V adapter such as is supplied with various laptops, then the supply's short-circuit protection circuitry usually shuts it down before it can damage resistor R. However, if the drive is an internal one, then the computer PSU's much higher current limit usually (?) blows the resistor open. When this happens the TVS diode is rendered ineffective, and the HDD's unprotected electronics is then hit with the full force of the overvoltage.

_________________
A backup a day keeps DR away.

So the preamp gets it power straight from the 5V Rail and not through the Smooth chip...

The preamp gets its +5V supply from the SATA connector, often via a small inductor (for noise filtering). Its negative supply (-5V) comes from an inverting buck regulator powered from the +5V supply, and with PWM control coming from the motor controller.

_________________
A backup a day keeps DR away.

Maybe this is a better diagram:

_________________
A backup a day keeps DR away.