There was a term commonly used years ago which I haven't heard for a long
time. Many commutators would fail because they "threw solder". The point
on the commutator that was soldered to the individual rotor winding had
heated, melted the solder, and "threw" it out of the connection, leaving
that winding either open or intermittent at best.

A friend from my youth was an auto-electrician, and apparently, back then,
this was a common occurrence on starter motors and the like. The term that
he used for the condition was "flung" as in 'it's got a "flung" armature'

I knew what that one meant, but the one that I never got in terms of where
the phrase came from was "drop testing" which I believe referred to the
resistance checking of the armature windings across opposite brass
commutator segments, as described here by someone else.

Arfa