I found a donor with good match, part number, MLC number & first two lines of Serial number on the PCB. I was going to replace it & try it first, before replacing the firmware (ROM IC). Is it even risky to try without changing the ROM??


I read the below excerpt from some data-recovery/hd-repair site, was a little worried:
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WARNING IF YOU CHANGE A PRINTED CIRCUIT BOARD WITH A NON MATCHING PCB... SUCH AS DIFFERENT FIRMWARE, LAYOUT, OR MICRO CONTROLLER NUMBERS, YOU WILL RUN A HIGH RISK OF FAILURE AND FURTHER DAMAGE!
Yes there's a high chance... YOU WILL SEE SMOKE!!!!!!

If you have an exact match to the PCB you want to attempt swapping, the risk will be minimal but what allot of people don’t realize, is that code can change overtime even with exact matching parts.

What this means is... if you were to purchase two NEW exact hard drives at the same time from the same batch and then swapped there PCB's to each other, you would most likely be successful!

Try that same scenario 6 months after heavy use... and results will could be very different
There's a high chance that each PCB has made themselves unique to each drive!

How can this be?
Its called SMART Technology where the hard drive is designed to reconfigure itself during operation to maximizing performance and protecting data. If a sector is read slow but functional the drive will remap this sector as bad and move this sector creating changes to track and sector information in firmware
Now this new reconfigured information is unique to the drive, and can cause this PCB to be incompatible with any other drive of matching numbers.
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Thanks!

Sometimes if you put a PCB from a donor on to a patient drive without changing the NVM chip you can mess up both the patient and the donor drives firmware. This means that your donor will no longer work with its original board and your patient will not work even if you change the NVM chip.

I can’t see how you can get smoke unless the PCB is really far off (like from some different model drive).

(Assuming there is no short in the motor or actuator windings of your patient drive.)

Thanks much DrNJ!

Lets say I try the donor pcb with donor NVM, it does not work, corrupts the donor NVM - how will this corrupt patient NVM data??
Now I will try with the patient NVM (which is fine) on the donor PCB (which should be fine too)


These surface mounted chips are kinda hard to deal with, all I can try is take some help from lab guys & solder it using regular solder iron (with a sharper tip, maybe??). I want to make sure the chip does not get too hot.

I have two options both are risky:
1. Change the NVM/ROM before trying out the new pcb - hard to solder surface-mounted chip.
2. Try without changing the NVM chip - risk of corupting the firmware

Also can you please enlighten me as to which one the ROM/NVM chip is (google didn't help, sorry!):
http://www.kuroduction.com/blog/mt/arch ... 831-02.jpg

Thanks for taking the time.

(oh yeah, its possible to corrupt the firmware in the system area of the patient drive platter)

no it is not, drive will clang, if You change rom it will work
did it 1000 times

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Thanks helpdisc! You meant, "no it is not safe to try without rom change", right??

Anyway, I'm going to change the ROM before I try it. How do you guys work with these surface-mounts??? Just be careful with regular solder??
Also I was assuming the chip on the left in the link below, 25FV051T was the ROM, correct??
http://www.kuroduction.com/blog/mt/arch ... 831-02.jpg

I'm a super noob, thanks for taking the time... (I tried to read on the web, unfortunately its got very less material on this data recovery field)

Please read the post above.
I have two chips that are 8pin in my IBM deskstar IC35L080AVVA07-0:
25FV051T & S93C6 (similar to the pic in above post)
Which one is the firmwave chip??

Both.

pepe

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