Logic Board Transplant Questions


MDL: WD3200JD-00KLB0

DATE: 08 MAY 2005


PCB: 2061-701336-B00 AB


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I have spent all day reading this forum and others, and have learned a lot having started near zero. Particularly thanks to fzabkar. I just need a few things clarified.

My HDD crashed while running XP, briefly gave some error message I did not see myself, and shut down. No prior sounds or signs that it was failing. Now BIOS will not recognize the HDD, and it doesn’t spin up at all.  I noticed it got very hot/smelled slightly burnt in one single spot on the logic board. Took off logic board to inspect drive side, and there is apparently a burnt out chip in that same area. I believe this chip is “L6283, SMOOTH, spindle motor + VCM controller, ST Microelectronics” according to fzabkar’s HDD IC file.


  1. Is the burnt out chip the “motor control chip” (so motor control chip is aka VCM controller )?

  2. Do the photographs indicate I need a new PCB and should ignore trying to find and test the TVS diode (I was hoping for that easier solution)? If No, where exactly is the TVS diode on my board? I can’t find an image of a similar looking board as mine.

  3. What are the minimum specs that need to match up when getting a replacement PCB? I haven’t been able to clarify if I just need to match the PCB #? Or both the PCB # and the MDL #? Or just the MDL #? (I am aware that I will need to transfer the U12 firmware chip and I already know how to solder.)

  4. Is my U12 firmware chip the small, 8-legged creature between the burnt VCM and the MCU, directly right of the screw hole in this image? –  [

    ]( “CloseUp2.jpg”)

Thanks in advance, and especially to fzabkar, I learned just about everything I needed from your posts!



1/ The SMOOTH chip is a combo controller. It controls the spindle motor, voice coil motor (VCM), and the onboard DC-DC converters. The datasheet for a similar chip (L7250) should explain what it does:


2/ I don’t see any TVS diode on your board. Unfortunately older boards weren’t protected from overvoltages. The YWW (Year / Week) date codes on the chips would suggest that your PCB was manufactured in about April of 2005.

3/ I don’t know the exact requirements for matching PCBs. That question is best answered by a data recovery professional. You may like to ask “raptor_pa” at …


FWIW, I believe the DCM (Drive Configuration Matrix) is very important when matching mechanical parts, but not when matching PCBs.

4/ The M25P10VP chip at U12 is the serial EEPROM. I don’t know if your older model HD has “adaptives” like the current models, but you can confirm this with raptor_pa.


Thanks for all the information and your time, fzabkar. Identifying and getting to learn about the individual chips is above and beyond helpful.

No TVS diode might explain a lot. I think the cause was power surge. That or defect, since these boards seem to blow out left and right.

I found and ordered a same-model HDD on eBay. It was made just days before mine and the DCM is 1 letter off. I’m told there’s a chance it will work without having to transplant the firmware chip. There is also a person on eBay selling PCBs with seemingly more selection and stock than most of the online stores. I was given the impression he can flash your firmware to the new PCB so you don’t have to transplant the chip, but he said he couldn’t do it for my model.