WD PC Board Parts

[Singinwolf]

Greetings to All,
I have 2 WD HD's that were involved in a PSU failure.
On both PC boards the U1 chips were cooked.
The first drive is a WD 1600 drive
MDL: WD1600JB-00GVA0
DCM: HSCHNT2AH
U1 CHIP INFO:SMOOTH L2683 1.3, ....D VH, 99 302, ST E (I can't identify the info before the "D" due to the chip being burned)
The second drive is a WD 2500JB
MDL: WD2500JB-00REA0
DCM: DSBHCTJCH
U1 CHIP INFO: SMOOTHL6283 1.3, 99213 VH, 99 615, ST e3 in a circle.
Questions:
What is the U1 chip for and/or what does it control?
Can I purchase the chip to replace them on the board to try to get these drives up and running to retrieve the data?
If so where can the chips be purchased and about how much should they cost.

Please note that on the attached photo the board on the left is the WD1600 PC board and the board on the right is the WD2500JB PC Board.

Thanks for any help you may be able to give me.
Don

Attachments

[shaun]

It's the motor combo chip - it communicates with the CPU via serial lines and controls the spindle motor, the voice coil motor and usually generates some auxilliary voltages. Chances are that more parts are blown, including the CPU (one board has external flash ROM with needs to be swapped onto a replacement PCB) and probably the head preamplifier within the HDA.

[Singinwolf]

Shaun,
Not what I wanted to hear . I was hoping that I could just change out the chips and be able to retrieve the data. When you say swap the rom chip I assume that you are referring to U12. Both boards have the U12 chips on them.
I guess the next question is where do I get replacement boards to change the ROM chips to so I can see if the head preamp. is fried as well?
Thanks for the response,
Don

[pepe]

U need the following:
701265 PCB for the GV
701292 PCB for the RE
then swap U12.

pepe

[Singinwolf]

Pepe,
Thanks Again for your help and information!
I have a few questions.
Where can I get the PCB you have indicated?
Also what are the chances that the head Preamps are bad?
The changing of the ROM chips is an non-issue.

By the way I read the link you suggested along with info from other sites and forums and see what you were referring to with regards to opening the drives to replace the platters.
Thanks,
Don

[r3712]

If you do all suggested and chip will blow again - it's preamp.