Hi @badgerisking ,
Did you test the motor windings with an Ohmmeter to make sure that the motor is OK, you didn’t say?
Here’s an image of part of the motor circuit taken from the [https://elektrotanya.com/sony_wm-f17.pdf/download.html|service manual] for the player. Be patient when going to download it, as it takes a little while to go from processing to download after you have passed the recaptcha check.
[image|2132622]
(click on image to enlarge for better viewing)
The manual has all the component part numbers as well. If the motor itself is faulty, searching for ''Sony X-3317-234-1'' only gives the one result for a supplier who states that it is NLA.