My knowledge is OK for comprehension when I read someone's description of circuit operation - when I might appreciate a certain diode must be a zener - but much more flakey when I'm trying to work it out with no description and no diagram. I'd be more forthcoming but the job is off-topic and I'm keen not to try anyone's patience.
> Don't get too carried away of course - it'd be a shame to destroy the device in the act of trying to identify it.
You read my mind.