Fixing small plastic... things
ard at p850ug1.demon.co.uk
Tue Dec 7 14:06:05 CST 2010
> We'll see how this works out with the glue. Fabricating replacement
> parts might be a bit of an undertaking -- some of the fingers are like
> the ones in my photos, a single, small plastic unit maybe a few
> millimeters wide. I can see fabricating new ones, though they're small
> enough that precision might be an issue. Others are part of a larger
> set of fingers on a single "tube"of plastic maybe 6-8 centimeters in
> length, these I suspect it will be difficult to replace.
What I would trty to do in the latter case is make the spindle and fingers
separately (the latter having a hole for the spindle, of course) and then
fix then together using either setscres, solder (soft solder or silver
solder) or loctite. Not having seen the machine I don't know if this is
possible, of course.
> >> The bad news is that even with the mechanism fixed, the machine still
> >> exhibits the same problem. I'm wondering if it's the delay line memory
> > Other than the physical damage, do you have any reason to suspect the
> > delay line system at thiis point?
> Not really. The physical damage was such that the dent looked as if it
> might actually be deep enough to be touching the delay line wire inside,
> potentially dampening the pulses. I opened it up this evening (had to
> gently hack off some rivets holding it shut) and gently hammered out the
> dents in the aluminum enclosure. No difference in behavior after
> reassembling it and hooking it back up, alas. But at least I can
> eliminate that particular aspect as a problem.
Indeed yse. As I read someehwere the comment 'I've checked every darn
compoennt in the <foo> circuit and I can;tfindanything wrong' should
imply (assuming that the tests are valid) that hte problem is not in the
<foo> circuit but elsewhere. And that is a step forward.
> >> up a service manual.
> > Did such a thing ever sxist?
> I hope so. I'd guess that a machine like this, of this vintage, would
> have such a manual. Not sure where to find one, though :).
I wonder if it was ever available outside the factory, thohgh (some
companies did not release service manuls :-(). Or if it contained full
schematics or if it was what I generally call a 'boardswapper guide'. HP
cdesktop cacluator service manuals are invariably the latter which has
caused me to spend many hours with a contiuity tester, pen and paper...
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