HDS721050CLA662 Busy mode experience

Case for experience.
HDS721050CLA662 motor spinning but head not moving. And drive in busy. I tried a donor pcp for head moving check. Head not moved also with donor PCB. I guessed head stacked somewhere.
I opened drive. Head and platter looks fine. And I decide to transfer rom to donor. And
Case solved. Drive working properly now.
Just want to share. I am surprised for solution.