I'm beginning to doubt whether your techie actually knows anything about data recover from a failed hard drive? :SYou never, never, never open a hard drive exposing the platter in anything other than a clean room, if data recovery is your top priority! That HD read/write head floats microns about the surface, and any dust or particles can now scratch that surface, permanently destroying your data. As an example, smoke particles or fingerprints are said to be about 2x-15x larger than the read/write head gap.
All I can say is good luck at this point. Not even a pro data recovery company will likely be able to help now. So won't have that option. Nor the PCB replacement longshot, which is now a waste of money. Better start re-constructing that Excel spreadsheet. Sorry!
