I have fixed a ton of drives, in general. Board replacements, swapping platters, head swaps, etc. Some takeaways: I started doing this under tupperware, and that worked. I built a "cleanroom" out of a new sandblasting cabinet, and that worked better. Later i built a laminar flow bench out of a cheap kobalt tool-box and some plexiglass, and that was better still.

Swapping the control boards works on some makes (wd), make certain it is exactly the same model and revision. exactly. "close enough" never worked for me, not even once.

By far just a slight "spin" by hand along the axis of travel of the disk, a quick gentile flicking motion, works to unfreeze the spindles of most stuck drives.

Some drives responded to a gentle heating of the spindle bearing with the hot air.

Use dd_rescue.

"Spinrite" is complete horse-shit, don't listen to anyone saying otherwise.

Most drives people brought in were just corruptions, photorec and it's associated programs (testdisk) are also invaluable..