IBM Deskstar40GB disc not detected by system (circuit board)

Hi All
I have a IBM Deskstar 40 GB 7200 RPM disc. Due to some light
fluctuation some problem occurred with it and it is now not being
detected by the system.
I got it checked and i was told that its main board will have to be
changed.
But the problem is that another board was installed on it, it was
detected but the size was shown as zero bytes .
Is there some compatibility issue..the board that was changed was from
the same model. There some important data on the disc that i want to
recover.
Is there some specific things that have to be seen while replacing the
main board of it with a similar board from a similar model. Can
anyone help me out. I will really appreciate it.
Regards

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