I got it to school and began getting input from other classmates on potential diagnoses, we suspected the gear train or the mainspring. The mainspring is a long and tough metal spring that gets coiled into a small drum, when wound it contains considerable force and is also the source of energy for mechanical watches.

I got it to my professor to hear our potential thoughts and get his hypothesis. He masterfully checked out a few areas and "probably a broken mainspring."

He handed it back to me. He also cautioned against being hasty in taking apart watches with value before having more training, giving me anecdotes of students past who caused considerable damage to some of their rare and valuable watches. I think he saw that look in my eye and knew that I wouldn't be deterred.

Later, I solicited some guidance from a second year student, the second years have been working on the ETA 2824 movement, a very widespread and, to some degree, standardized movement. The Tudor that I was taking apart runs on the ETA 2784, which is a very similar predecessor to the 2824 (I already just say random numbers when referring to movements in hopes that someone will understand, these are going to be annoying to memorize). So at the very least, it would be good practice. Real world wear and tear on a watch movement is quite different than simulated wear and it varies wildly from watch to watch; this is where the problem solving skills of the watchmaker come into play.