A few years ago I purchased a watch repair course called WATCH REPAIR IN A BOX that covered the repair of battery and capacitor powered watches. I do not know if the course is still available or not but when I bought it the cost was around $10.00. The course was put together by a working watch repair techhician and did a good job showing how to repair electronic watches. Understanding how these devices work requires a knowledge of basic electronics, switching circuits, flip flops, bit level software development, and shift registers and is beyond the academic realm of watch repair. Repairing them however does not require a knowledge of how they work. First of all, if you take an oscilloscope and trace the timing signal from the crystal down through the circuitry and find out where it stops, so what. There is nothing you can do to fix it and will have to replace the entire movement anyway. So the repair process boils down to this: 1). Check the power source by replacing with a battery or capacitor known to be good. 2). If it still does not run, replace the entire movement. There may be a rare occasion when a high end Seiko comes in and it might be worth while to replace the crystal but most of the common movements are so inexpensive it is cost prohibitive to do this. There are only a small number of companies that manufacture these movements: ELEMEX, ETA, FE (French Ebauche), HARLEY RONDA, HATTORI, and ISA. Check out some of the suppliers to get a feel for the cost of these movements: Jules Borel, Esslinger, Cas-Ker, Frei and Borel. Get some old movements that do not work and practice putting new movements into the cases. If the watches were sent to a factory service center for repair that is all they would do.