WD Alignment

[AJ2008]

WD5000xxx with head failure is proving to be very difficult to recover from. I have attempted disabling heads and recalculating defect tables, have attempted head replacement with compatible donors, incompatible donors, different capacity donors, have performed head replacement while maintaining alignment of all screws (each screw drawn around with a marker before lid removed), I have limited success with these, obviously as a result of the alignment.

If I take a fully functioning donor and remove heads with no care for alignment, and replace the same heads into the same drive, the drive will work as normal. Surely if alignment was such a big issue this would be impossible?

Also, one thing I have not tried is to clean heads with cleaning solution such as isopropyl alcohol. Is there much success associated with this?