[EXTENDED] Repairing my Seiko UC-2000, UC-2200 Watch and Controller

One of my white whales; the Seiko Wrist Information System UC-2000 and full Controller UC-2200

It was sold as, and received verified not working. I had repaired it before making this video, so I decided to record everything I'd done to get this wonderful device back in operation!
TL;DW: A bad capacitor and corrosion in the control unit (base station), and bad solder joints and broken communication coil in the watch.

This is the full, uncut recording (well mostly; I took a few long pauses out). The shortened and repair-centric version is here    • [ABRIDGED] Repairing my Seiko UC-2000...  

Image gallery here: https://imgur.com/gallery/H5PZu19

It can run BASIC*, Games^, and Save+Print* Memos^!
* Some functions such as BASIC and the calculator require the base station, where the watch simply performs as the display terminal
^ Games or Memos can only be loaded one at a time

I also compare the interoperability with the Seiko UC-3000 and UC-3100 Memo-only version of the set. One thing I didn't mention is that the UC-2200 control unit seems to disable keys depending on the mode it thinks its in which is most likely why text typing didn't work on the UC-3000 as the controller will not stay in enabled modes if the watch is removed

Chapters:
00:00 Intro, unboxing
01:48 Device Overview
06:05 Control Unit Problem, Fix
09:24 Watch Problem, Fix
22:48 Testing, adjusting
27:45 BASIC Demo
28:57 Application Demo
30:19 Loading another Game, Playing
31:51 Testing the beeper
32:26 Trying the phone Control app
33:51 Wrapup, or...?
35:00 Interoperability testing UC-3000
39:12 Print Demo