it's ROM chip. you can find out same model of your PCB and swap this ROM chip to good PCB. that will help for your drive if it's just PCB got problem

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data recovery service[/b]

Thanks nande, but how can I tell if the fuse N is open or not? Can I swap the fuse N from the donar PCB?

For the Marvell MCU, I found that the model 88i6735A-BAN1 is the same as the donor PCB, but the next line the original MCU FP18561A is different from the donor PCB. I don't know if it affects the recognization of the HD device in BIOS

Measure the resistance of the fuse with a multimeter.

The fuse N is open. I have compared it with the new PCB. So can I just short the fuse ?

Measure the resistance between each side of the fuse and circuit ground. Compare it against your new PCB. If there is a low resistance, then this would suggest that another component is damaged.

yes, the new PCB have very low resistance.

Just to confirm, are you saying that there is a low resistance between the fuse and ground on your new PCB?

yes, it's about 0.13Ohm

I think you may have misunderstood me. Measure the resistance between the test point labelled "+5V fused" and any point marked "ground", eg pins 12 and 10 of the SATA power connector, or the ground plane on the left. Compare these measurements with your good board.

See http://www.users.on.net/~fzabkar/HDD/MHW2080BH_fuse.jpg

the +5V pin 9,8,7 doesn't show any resistance with the ground on the old board.

It means there is something wrong with your old pcb. Easiest fix is to swap the ROM of your bad pcb to the new pcb.

You are correct, but the donor PCB MCU is different from the original PCB
The donor PCB
88i6735A-BAN1
FP18S61
The original PCB MCU is
88i6735A-BAN1
FP18S61A

If I swap the Rom, will it work? I don't know if the different MCU will destroy the harddisk data.

Check both PCB, if the same B10x marked on pcb then it should be ok to ROM swap.

both PCB is the same model, but I am unable to heat the ROM out using soldering iron. Can you let me know what I need to do?

The ROM for the original PCB
25P10AVG
HPAAD VS
KOR 630
firmware:07FFAA-0000001C
Can you let me know what tool I need in order to flash the ROM or swap the ROM?

Samuel. Swaping the rom out is easiest way. Anything else is EXTRA work and a lot harder for DIY.
Its like a patient coming to a doctor
- Hi i have heart problems
- Here take those pills for a week.
- I cant open the bottle with pills. Tell me how do i do an open heart surgery on myself.

380 C , add some flux on both sides. Axe like soldering tip to cover all legs on 1 side in 1 go. Or id suggest finding an electronics store that can do it for you.

It is most probably a lead-free soldered PCB, with common soldering iron it will end in a disaster if the skill is not enough.... good luck !

P.S. even with the most care and using advanced equipment, reworking of PCBs has not always "happy ending" : some PCBs are prone to delamination and a lot of other bad behaviour while other are much more easy and safe to work with.

Ask someone else to do it. On this board, it is fairly easy if you have some soldering skills. Sorry, this is my last post in this topic. Everything has already been given to you.

I have found someone to perform the soldering work for me. The data is able to read now.
Many thanks for all of you. Thanks for your guidance and patience.
Thanks again to fzabkar, nande, z007, networkpc3000, BlackST and Alexii

Congrats Samuel =)