Any one can tell me where is u12 chip in WD3200AAKS-00L9A0. If not found so where firmware save in this hard disk. My Wd3200AAKS PCB not working (Not Dedect). i am trying to find where is firmware save.

There is a high chance your pcb doesn't have a U12.
Post a clear picture of the component side of the pcb and someone will pinpoint it for you.

On the other hand, what makes you sure your hdd has a pcb problem?

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If your board looks like this one ...

http://pcb-hdd.com/images/WD3200AAKS-75 ... %20PCB.jpg

... then U12 is vacant, which means that the firmware is inside the Marvell 88i6745-TFJ1 MCU. This particular MCU has a fault that sometimes mimics a head or media problem.

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Thanks for Reply and sent jpg file, can you tell me. how i copy wd3200AAKS firm ware to new pcb bcz. new pcb bord is same but model is different.

A small part of the boot firmware is in flash memory on the PCB, but the major part of the firmware is in the System Area on the platters.

That said, there is not enough information to determine whether your problem is a PCB fault, or whether there is an internal fault.

As for copying the flash contents from one PCB to another, some PCB suppliers include such a service for $20. In fact one board supplier who is also a member of this forum offers such a service at no extra cost.

To retrieve firmware modules and ROM data from the HDD, see the MHDD scripts here:
http://yura.projektas.lt/files/wd/mhdd/index.html

Your drive is a ROYL, and you will need MHDD ver 4.5.

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