On Sat, 23 Jun 2018 20:37:19 -0400, Flasherly
wrote:

Pulled it apart..

-
And another intermittent key, with yet another potentially marginal.
Resoldered both and seems repaired, as does the first re-solder, which
is also holding for good operation.

These Chinese keyswitches are OK. It's the soldering that's crap,
wherever that occurred. Hardly any, a miniscule amount of solder
splatter on the board...looking for handiwork involved. Seems it
would be machine/robotic soldered. Looking over the actual two-prong
keyswitch contacts, I'm not so sure about an extent of manual
soldering involved. The contacts, a lot to most vary to the extent of
very little solder covering those keyswitch pins.

The rest of the board, LED and other junction/components,
contact-traces are too small to be feasible for hand-soldering. Seems
it then indicates stages. Everything up to a point machine-production
soldered, and then, possibly in my case, machine production of
keyswitch contacts may be spotty, so it's gone over, scabbed by human
corrective soldering. Not conclusively by any approximation to QC.

That's three faulty solder keyswitches and could very well mean more
on the way. The plus is that fixing the keys is minor, not beyond
basic soldering proficiency, provided it stays that way, a little
tedium here and there, and nothing more fails beyond that skill level.