6 Aug
2012
6 Aug
'12
10:34 a.m.
Hmm. It looks to me like the metal with the black goo on it (which is
scraped off with a razor in the video) once had a piece of thin foam
glued to it.
Like many things made out of that type of foam, (i.e. keytronic
keyboards, and the anti-noise foam inside certain dec, sun, and other
older machines), the foam has turned into sticky goop after a number of
years (and probably exposure to ozone inside the printer), causing the
solenoid to stick.
Just a guess, since I don't have one of those nearby to take apart.
I've had a rather more unpleased problem recently with such foam. It was
used in some 1970s SLR cmaeras to cushion the pentaprism retainer. And it
appears that whatever it decays into will attack the silvering on the
prism. I've got a couple of cmaers where this has occured (the latest was
an Alympos OM1 :-(). Certainyl somethign to look for if you colelct old
cameras or indeeed anything else where said foam is used on clamps, etc.
-tony