We work really closely with our assembly facility (they're about a 2 hour drive from our office, so they're local-ish), and with their help, we reduced the field failure rate on meters from about 2.5% on the first production batch of Clocks to about .6% on batch #2. (If you're one of the unlucky few with a bad meter, let us know, we repair/replace at no charge).
Most issues were traced to debris from a wire brush used for cleaning parts at the meter factory (we think they passed testing at the point of origin and debris dislodged and jammed the mechanism in shipping) and now we run a more sophisticated component screening test at our facility.
By working closely with out assembly techs, we learned it was much easier to spot a bad meter when you had a good one running side by side with it. When they were synchronized, any glitch or jump in the bad meter really stood out.
So based on that information, we've upgraded from the single unit tester we started with on batch #1, to the double unit tester used for batch #2, to the 6 unit Franken-Test-Rig we made for batch #3.
The top pictures shows the full test stand and the bottom picture shows our mess of a PCB hack we made.
Basically, we wanted all the meters running in sync, so we had to add 6 parallel circuits to our standard Clock PCB. We used copper tape to create additional traces, soldered on some resistors, and wired it up to some 3d printed test stands. Boom! Franken-Test-Rig!
This should make life easier and faster for our assembly techs.