The guy behind this is not just very competent, but also generous and systematic in sharing his analysis. I have learned a lot about practical electronics and was able to chose a modest DMM that altough satisfying for general use, is not good enough for complete quartz module testing. The search continues.
Indeed, things changed after I had tightened the cannon pinion (I guess...) so I first removed the minute wheel and then the cannon pinion but unfortunately it made no difference at all. And you're right, I never mentioned it, but thanks a bunch for reminding me! These things are so easy to overlook. I've made sure the entire dial train (motion works) is running smoothly.
Picked up a vintage triple lot last night. A chunky Timex SSQ Quartz LCD, a Texas Instruments LCD and an electronic Sheffield based on the Jungans. Hopefully I can get them working. I'm particularly interested in the Sheffield as the watch was recently discussed here.